Subjects -> BIOLOGY (Total: 3416 journals)
    - BIOCHEMISTRY (264 journals)
    - BIOENGINEERING (141 journals)
    - BIOLOGY (1630 journals)
    - BIOPHYSICS (49 journals)
    - BIOTECHNOLOGY (265 journals)
    - BOTANY (249 journals)
    - CYTOLOGY AND HISTOLOGY (31 journals)
    - ENTOMOLOGY (75 journals)
    - GENETICS (171 journals)
    - MICROBIOLOGY (283 journals)
    - MICROSCOPY (12 journals)
    - ORNITHOLOGY (28 journals)
    - PHYSIOLOGY (72 journals)
    - ZOOLOGY (146 journals)

BIOLOGY (1630 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 29)
Achievements in the Life Sciences     Open Access   (Followers: 8)
ACS Pharmacology & Translational Science     Hybrid Journal   (Followers: 2)
ACS Synthetic Biology     Hybrid Journal   (Followers: 31)
Acta Biologica Colombiana     Open Access   (Followers: 7)
Acta Biologica Hungarica     Full-text available via subscription   (Followers: 5)
Acta Biologica Sibirica     Open Access   (Followers: 2)
Acta Biologica Turcica     Open Access   (Followers: 1)
Acta Biologica Venezuelica     Open Access  
Acta Biomaterialia     Hybrid Journal   (Followers: 30)
Acta Biotheoretica     Hybrid Journal   (Followers: 3)
Acta Chiropterologica     Full-text available via subscription   (Followers: 6)
acta ethologica     Hybrid Journal   (Followers: 4)
Acta Fytotechnica et Zootechnica     Open Access   (Followers: 1)
Acta Limnologica Brasiliensia     Open Access   (Followers: 4)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Musei Silesiae, Scientiae Naturales     Open Access   (Followers: 1)
Acta Neurobiologiae Experimentalis     Open Access  
Acta Parasitologica     Hybrid Journal   (Followers: 12)
Acta Scientiae Biological Research     Open Access   (Followers: 1)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis     Open Access   (Followers: 1)
Actualidades Biológicas     Open Access   (Followers: 1)
Advanced Biosystems     Hybrid Journal  
Advanced Health Care Technologies     Open Access   (Followers: 9)
Advanced Journal of Graduate Research     Open Access   (Followers: 1)
Advanced Nonlinear Studies     Hybrid Journal  
Advanced Quantum Technologies     Hybrid Journal  
Advanced Studies in Biology     Open Access   (Followers: 1)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Bioinformatics     Open Access   (Followers: 20)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
Advances in Biology     Open Access   (Followers: 12)
Advances in Cell Biology/ Medical Journal of Cell Biology     Open Access   (Followers: 30)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 14)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Ecological Research     Full-text available via subscription   (Followers: 44)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 18)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 9)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in High Energy Physics     Open Access   (Followers: 22)
Advances in Human Biology     Open Access   (Followers: 5)
Advances in Life Science and Technology     Open Access   (Followers: 20)
Advances in Life Sciences     Open Access   (Followers: 7)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 26)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 7)
Advances in Structural Biology     Full-text available via subscription   (Followers: 6)
Advances in Tropical Biodiversity and Environmental Sciences     Open Access   (Followers: 3)
Advances in Virus Research     Full-text available via subscription   (Followers: 6)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 11)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 3)
Ageing Research Reviews     Hybrid Journal   (Followers: 12)
Aging Cell     Open Access   (Followers: 25)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
AJP Cell Physiology     Hybrid Journal   (Followers: 18)
AJP Endocrinology and Metabolism     Hybrid Journal   (Followers: 25)
AJP Lung Cellular and Molecular Physiology     Hybrid Journal   (Followers: 3)
Al-Kauniyah : Jurnal Biologi     Open Access  
Alasbimn Journal     Open Access   (Followers: 2)
Alces : A Journal Devoted to the Biology and Management of Moose     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 14)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 9)
American Journal of Bioethics     Hybrid Journal   (Followers: 16)
American Journal of Human Biology     Hybrid Journal   (Followers: 18)
American Journal of Medical and Biological Research     Open Access   (Followers: 10)
American Journal of Plant Sciences     Open Access   (Followers: 21)
American Journal of Primatology     Hybrid Journal   (Followers: 16)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 81)
Amphibia-Reptilia     Hybrid Journal   (Followers: 6)
Anadol University Journal of Science and Technology B : Theoritical Sciences     Open Access  
Anadolu University Journal of Science and Technology : C Life Sciences and Biotechnology     Open Access   (Followers: 2)
Anaerobe     Hybrid Journal   (Followers: 4)
Analytical Methods     Full-text available via subscription   (Followers: 13)
Anatomical Science International     Hybrid Journal   (Followers: 3)
Animal Cells and Systems     Hybrid Journal   (Followers: 5)
Animal Models and Experimental Medicine     Open Access  
Annales de Limnologie - International Journal of Limnology     Hybrid Journal   (Followers: 1)
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales Universitatis Mariae Curie-Sklodowska, sectio C – Biologia     Open Access   (Followers: 1)
Annals of Applied Biology     Hybrid Journal   (Followers: 8)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 19)
Annals of Human Biology     Hybrid Journal   (Followers: 6)
Annals of Science and Technology     Open Access  
Annual Research & Review in Biology     Open Access   (Followers: 2)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 15)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 26)
Annual Review of Cancer Biology     Full-text available via subscription   (Followers: 4)
Annual Review of Cell and Developmental Biology     Full-text available via subscription   (Followers: 42)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 27)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 13)
Anthropological Review     Open Access   (Followers: 24)
Antibiotics     Open Access   (Followers: 9)
Antioxidants     Open Access   (Followers: 5)
Antioxidants & Redox Signaling     Hybrid Journal   (Followers: 9)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apidologie     Hybrid Journal   (Followers: 5)
Apmis     Hybrid Journal   (Followers: 1)
APOPTOSIS     Hybrid Journal   (Followers: 9)
Applied Biology     Open Access   (Followers: 2)
Applied Bionics and Biomechanics     Open Access   (Followers: 7)
Applied Vegetation Science     Full-text available via subscription   (Followers: 10)
Aquaculture Environment Interactions     Open Access   (Followers: 4)
Aquaculture International     Hybrid Journal   (Followers: 26)
Aquaculture Reports     Open Access   (Followers: 3)
Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society     Open Access   (Followers: 7)
Aquatic Biology     Open Access   (Followers: 8)
Aquatic Ecology     Hybrid Journal   (Followers: 38)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 16)
Aquatic Science and Technology     Open Access   (Followers: 4)
Aquatic Toxicology     Hybrid Journal   (Followers: 23)
Archaea     Open Access   (Followers: 4)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biological Sciences     Open Access  
Archives of Microbiology     Hybrid Journal   (Followers: 10)
Archives of Natural History     Hybrid Journal   (Followers: 8)
Archives of Oral Biology     Hybrid Journal   (Followers: 3)
Archives of Virology     Hybrid Journal   (Followers: 5)
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos do Museu Dinâmico Interdisciplinar     Open Access  
Arthropod Structure & Development     Hybrid Journal   (Followers: 2)
Arthropods     Open Access   (Followers: 1)
Artificial DNA: PNA & XNA     Hybrid Journal   (Followers: 3)
Asian Bioethics Review     Full-text available via subscription   (Followers: 3)
Asian Journal of Biodiversity     Open Access   (Followers: 5)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Biology     Open Access   (Followers: 2)
Asian Journal of Biotechnology and Bioresource Technology     Open Access   (Followers: 1)
Asian Journal of Cell Biology     Open Access   (Followers: 6)
Asian Journal of Developmental Biology     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 5)
Asian Journal of Nematology     Open Access   (Followers: 4)
Asian Journal of Poultry Science     Open Access   (Followers: 5)
Atti della Accademia Peloritana dei Pericolanti - Classe di Scienze Medico-Biologiche     Open Access  
Australian Life Scientist     Full-text available via subscription   (Followers: 2)
Australian Mammalogy     Hybrid Journal   (Followers: 8)
Autophagy     Hybrid Journal   (Followers: 4)
Avian Biology Research     Full-text available via subscription   (Followers: 6)
Avian Conservation and Ecology     Open Access   (Followers: 14)
Bacterial Empire     Open Access   (Followers: 1)
Bacteriology Journal     Open Access   (Followers: 1)
Bacteriophage     Full-text available via subscription   (Followers: 3)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Batman Üniversitesi Yaşam Bilimleri Dergisi     Open Access  
Berita Biologi     Open Access   (Followers: 1)
Between the Species     Open Access   (Followers: 1)
Bio Tribune Magazine     Hybrid Journal  
BIO Web of Conferences     Open Access  
BIO-Complexity     Open Access  
Bio-Grafía. Escritos sobre la Biología y su enseñanza     Open Access  
Bio-Lectura     Open Access  
BIO-SITE : Biologi dan Sains Terapan     Open Access   (Followers: 1)
Bioanalytical Reviews     Hybrid Journal   (Followers: 2)
Biocatalysis and Biotransformation     Hybrid Journal   (Followers: 6)
BioCentury Innovations     Full-text available via subscription   (Followers: 1)
Biochemistry and Cell Biology     Hybrid Journal   (Followers: 17)
Biochimie     Hybrid Journal   (Followers: 6)
BioControl     Hybrid Journal   (Followers: 6)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 8)
Biodemography and Social Biology     Hybrid Journal  
BIODIK : Jurnal Ilmiah Pendidikan Biologi     Open Access   (Followers: 1)
BioDiscovery     Open Access   (Followers: 2)
Biodiversidade e Conservação Marinha : Revista CEPSUL     Open Access  
Biodiversitas : Journal of Biological Diversity     Open Access  
Biodiversity Data Journal     Open Access   (Followers: 4)
Biodiversity Informatics     Open Access   (Followers: 1)
Biodiversity Information Science and Standards     Open Access   (Followers: 2)
Biodiversity: Research and Conservation     Open Access   (Followers: 27)
Bioedukasi : Jurnal Pendidikan Biologi FKIP UM Metro     Open Access  
Bioeksperimen : Jurnal Penelitian Biologi     Open Access  
Bioelectrochemistry     Hybrid Journal   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 2)
Bioenergy Research     Hybrid Journal   (Followers: 4)
Bioengineering and Bioscience     Open Access   (Followers: 3)
BioEssays     Hybrid Journal   (Followers: 11)
Bioethics     Hybrid Journal   (Followers: 18)
BioéthiqueOnline     Open Access  
Biofabrication     Hybrid Journal   (Followers: 5)
Biofilms     Full-text available via subscription   (Followers: 2)
Biogeosciences (BG)     Open Access   (Followers: 12)
Biogeosciences Discussions (BGD)     Open Access   (Followers: 3)
Bioinformatics     Hybrid Journal   (Followers: 386)
Bioinformatics and Biology Insights     Open Access   (Followers: 12)

        1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Annals of Biomedical Engineering
Journal Prestige (SJR): 1.042
Citation Impact (citeScore): 3
Number of Followers: 19  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1573-9686 - ISSN (Online) 0090-6964
Published by Springer-Verlag Homepage  [2570 journals]
  • Advances in Human Induced Pluripotent Stem Cell-Derived Hepatocytes for
           Use in Toxicity Testing
    • Abstract: Abstract Induced pluripotent stem cells (iPSCs) can be differentiated into multiple cell types in the body while maintaining proliferative capabilities. The generation of hepatocyte-like cells (HLCs) from iPSCs has resulted in a new source for liver cells. Since healthy primary human hepatocytes and hepatic cells are difficult to obtain, HLCs are gaining attention. HLCs can be obtained from a continuous, stable source while maintaining their original donor genotype, which opens new avenues into patient-specific testing and therapeutics. Studies have utilized HLCs for toxicity testing to further understand their drug metabolizing capabilities. This review focuses on advances being made to achieve hepatic functions from HLCs, their current use in hepatotoxicity testing, and their potential for future liver-related toxicity evaluations.
      PubDate: 2020-03-01
       
  • Effect of Mold Geometry on Pore Size in Freeze-Cast Chitosan-Alginate
           Scaffolds for Tissue Engineering
    • Abstract: Abstract Freeze-casting is a popular method to produce biomaterial scaffolds with highly porous structures. The pore structure of freeze-cast biomaterial scaffolds is influenced by processing parameters but has mostly been controlled experimentally. A mathematical model integrating Computational Fluid Dynamics with Population Balance Model was developed to predict average pore size (APS) of 3D porous chitosan-alginate scaffolds and to assess the influence of the geometrical parameters of mold on scaffold pore structure. The model predicted the crystallization pattern and APS for scaffolds cast in different diameter molds and filled to different heights. The predictions demonstrated that the temperature gradient and solidification pattern affect ice crystal nucleation and growth, subsequently influencing APS homogeneity. The predicted APS compared favorably with APS measurements from a corresponding experimental dataset, validating the model. Sensitivity analysis was performed to assess the response of the APS to the three geometrical parameters of the mold: well radius; solution fill height; and spacing between wells. The pore size was most sensitive to the distance between the wells and least sensitive to solution height. This validated model demonstrates a method for optimizing the APS of freeze-cast biomaterial scaffolds that could be applied to other compositions or applications.
      PubDate: 2020-03-01
       
  • Encapsulation of Mesenchymal Stem Cells in 3D Ovarian Cell Constructs
           Promotes Stable and Long-Term Hormone Secretion with Improved
           Physiological Outcomes in a Syngeneic Rat Model
    • Abstract: Abstract Loss of ovarian function (e.g., due to menopause) leads to profound physiological effects in women including changes in sexual function and osteoporosis. Hormone therapies are a known solution, but their use has significantly decreased due to concerns over cardiovascular disease and certain cancers. We recently reported a tissue-engineering strategy for cell hormone therapy (cHT) in which granulosa cells and theca cells are encapsulated to mimic native ovarian follicles. cHT improved physiological outcomes and safety compared to pharmacological hormone therapies in a rat ovariectomy model. However, cHT did not achieve estrogen levels as high as ovary-intact animals. In this report, we examined if hormone secretion from cHT constructs is impacted by incorporation of bone marrow-derived mesenchymal stem cells (BMSC) since these cells contain regulatory factors such as aromatase necessary for estrogen production. Incorporation of BMSCs led to enhanced estrogen secretion in vitro. Moreover, cHT constructs with BMSCs achieved estrogen secretion levels significantly greater than constructs without BMSCs in ovariectomized rats from 70 to 90 days after implantation, while also regulating pituitary hormones. cHT constructs with BMSC ameliorated estrogen deficiency-induced uterine atrophy without hyperplasia. The results indicate that inclusion of BMSC in cHT strategies can improve performance.
      PubDate: 2020-03-01
       
  • Vitamin D 3 Release from Traditionally and Additively Manufactured
           Tricalcium Phosphate Bone Tissue Engineering Scaffolds
    • Abstract: Abstract Bone is a randomized, complex porous network which researchers have tried to mimic within bone tissue engineering scaffolds. The objective of this study was to understand the effects of random and controlled scaffold porosity on the release kinetics of vitamin D3 to determine if a designed porous structure was comparable in effectiveness on osteoblast proliferation to the randomized essence of natural bone. In this study, porous tricalcium phosphate (TCP) scaffolds were prepared by fugitive material removal method using naphthalene and 3D printing to model random and controlled porosity, respectively. Scaffold comparison was made based on open pore volume percentage of which naphthalene scaffolds had 45.8 ± 1.5% and 3D printed scaffolds had 48.9 ± 2.5%, Comparative analysis of traditional bioceramic processing to additive manufacturing is limited especially regarding drug release kinetics. Results showed the naphthalene scaffold surface area was only 0.3% that of 3D printed scaffolds due to the lower open pore interconnectivity. This increase in surface area produced higher release of drug and osteoblast proliferation in 3D printed scaffolds comparatively. By 11 days, osteoblast proliferation was enhanced by 64% from scaffolds manufactured using 3D printing compared to traditional processing. Understanding the effects of processing methods of TCP scaffolds on the release kinetics of vitamin D3 and the system effects on cells can aid in low load bearing applications for bone tissue engineering.
      PubDate: 2020-03-01
       
  • Development of a Colorectal Cancer 3D Micro-tumor Construct Platform From
           Cell Lines and Patient Tumor Biospecimens for Standard-of-Care and
           Experimental Drug Screening
    • Abstract: Abstract Colorectal cancer is subject to a high rate of mutations, with late stage tumors often containing many mutations. These tumors are difficult to treat, and even with the recently implemented methods of personalized medicine at modern hospitals aiming to narrow treatments, a gap still exists. Proper modeling of these tumors may help to recommend optimal treatments for individual patients, preferably utilizing a model that maintains proper signaling in respect to the derived parent tissue. In this study, we utilized an extracellular matrix-derived hydrogel to create a 3D micro-tumor construct platform capable of both supporting cells for long time durations and for high throughput drug screening. Experiments with cell lines demonstrated long-term viability with maintenance of cell proliferation. Furthermore, studies with several chemotherapeutics utilizing different mechanisms of action displayed differences in efficacy in comparing 3D and 2D cultures. Finally, patient colorectal tumor tissue was acquired and employed to reconstruct micro-tumor constructs, providing a system for the testing of novel chemotherapeutics against tumors in a patient-specific manner. Collectively, the results describe a system capable of high throughput testing while maintaining important characteristics of the parent tissue.
      PubDate: 2020-03-01
       
  • 3D Culture Facilitates VEGF-Stimulated Endothelial Differentiation of
           Adipose-Derived Stem Cells
    • Abstract: Abstract De novo vascularization of implantable tissue and whole organ constructs has been a significant challenge in the field of tissue engineering; the use of endothelial cell populations for this task is constrained by the cell population’s limited regeneration capacity and potential for loss of function. Thus, there is a need for a stem-cell population that may be induced into an endothelial cell phenotype reliably. Adipose derived stem cells (ADSCs) are multipotent cells that can be readily isolated from donor fat and may have the potential to be readily induced into endothelial cells. The ability to stimulate endothelial differentiation of these cells has been limited in standard 2D culture. We hypothesized that 3D culture would yield better differentiation. To study the influence of cell density and culture conditions on the potential of ADSCs to differentiate into an endothelial-like state, we seeded these cells types within a 3D cell-adhesive, proteolytically degradable, peptide-modified poly(ethylene-glycol) (PEG) hydrogel. ADSCs were either cultured in basal media or pro-angiogenic media supplemented with 20 ng/mL of VEGF in 2D and then encapsulated at low or high densities within the PEG-based hydrogel. These encapsulated cells were maintained in either basal media or pro-angiogenic media. Cells were then isolated from the hydrogels and cultured in Matrigel to assess the potential for tubule formation. Our work shows that maintenance of ADSCs in a pro-angiogenic medium in 2D monoculture alone does not result in any CD31 expression. Furthermore, the level of CD31 expression was affected by the density of the cells encapsulated within the PEG-based hydrogel. Upon isolation of these cells, we found that these induced ADSCs were able to form tubules within Matrigel, indicative of endothelial function, while ADSCs cultured in basal medium could not. This finding points to the potential for this stem-cell population to serve as a safe and reliable source of endothelial cells for tissue engineering and regenerative medicine purposes.
      PubDate: 2020-03-01
       
  • ECM in Differentiation: A Review of Matrix Structure, Composition and
           Mechanical Properties
    • Abstract: Abstract Stem cell regenerative potential owing to the capacity to self-renew as well as differentiate into other cell types is a promising avenue in regenerative medicine. Stem cell niche not only provides physical scaffolding but also possess instructional capacity as it provides a milieu of biophysical and biochemical cues. Extracellular matrix (ECM) has been identified as a major dictator of stem cell lineage, thus understanding the structure of in vivo ECM pertaining to specific tissue differentiation will aid in devising in vitro strategies to improve the differentiation efficiency. In this review, we summarize details about the native architecture, composition and mechanical properties of in vivo ECM of the early embryonic stages and the later adult stages. Native ECM from adult tissues categorized on their origin from respective germ layers are discussed while engineering techniques employed to facilitate differentiation of stem cells into particular lineages are noted. Overall, we emphasize that in vitro strategies need to integrate tissue specific ECM biophysical cues for developing accurate artificial environments for optimizing stem cell differentiation.
      PubDate: 2020-03-01
       
  • Independent, Controllable Stretch-Perfusion Bioreactor Chambers to
           Functionalize Cell-Seeded Decellularized Tendons
    • Abstract: Abstract Tissue-engineered decellularized matrices can progress clinical replacement of full-thickness ruptures or tendon defects. This study develops and validates a custom-made automated bioreactor, called oscillating stretch-perfusion bioreactor (OSPB), consisting of multiple, independent culture chambers able to combine a bidirectional perfusion with a programmable, uniaxial strain to functionalize cell-seeded decellularized tendons. Decellularized tendon matrices were seeded on their surfaces and within the tendon fibers with mesenchymal stem cells. Then, they were subjected to a bidirectional perfusion and programmed stretching cycles of 15–30–60 min on–off two times per day for 7 days of culture. In vitro analyses showed viable cells, homogenously distributed on the surface of the constructs. More importantly, cell-seeded decellularized tendon grafts undergoing cyclic load in our bioreactor had a superior production and organization of newly formed collagen matrix compared to static cultured constructs. The coherency and local alignment of the new collagen deposition within the inner injected channels quantitatively supported histological findings. The designed OSPB could be considered a unique, cost-effective system able to involve multiple independently controlled chambers in terms of biological and mechanical protocols. This system allows parallel processing of several customized tendon constructs to be used as grafts to enhance the surgical repair of large tendon defects.
      PubDate: 2020-03-01
       
  • Embryonic Mesenchymal Multipotent Cell Differentiation on Electrospun
           Biodegradable Poly(ester amide) Scaffolds for Model Vascular Tissue
           Fabrication
    • Abstract: Abstract Vascular differentiation of stem cells and matrix component production on electrospun tubular scaffolds is desirable to engineer blood vessels. The mouse embryonic multipotent mesenchymal progenitor cell line (10T1/2) provides an excellent tool for tissue engineering since it shares similar differentiation characteristics with mesenchymal stem cells. Although 10T1/2 cells have been widely studied in the context of skeletal tissue engineering, their differentiation to smooth muscle lineage is less known. In this study, we fabricated tubular electrospun poly(ester amide) (PEA) fibers from l-phenylalanine-derived biodegradable biomaterials and investigated cell-scaffold interactions as well as their differentiation into vascular smooth muscle cell and subsequent elastin expression. PEA scaffolds fabricated under different collector speeds did not have an impact on the fiber directionality/orientation. 10T1/2 cytocompatibility and proliferation studies showed that PEA fibres were not cytotoxic and were able to support proliferation for 14 days. Furthermore, cells were observed infiltrating the fibrous scaffolds despite the small pore sizes (~ 5 µm). Vascular differentiation studies of 10T1/2 cells using qPCR, Western blot, and immunostaining showed a TGFβ1-induced upregulation of vascular smooth muscle cell (VSMC)-specific markers smooth muscle alpha-actin (SM-α–actin) and smooth muscle myosin heavy chain (SM-MHC). Differentiated 10T1/2 cells produced both elastin and fibrillin-1 suggesting the potential of fibrous PEA scaffolds to fabricate model vascular tissues.
      PubDate: 2020-03-01
       
  • Inhibition of the Prostaglandin EP-1 Receptor in Periosteum Progenitor
           Cells Enhances Osteoblast Differentiation and Fracture Repair
    • Abstract: Abstract Fracture healing is a complex and integrated process that involves mesenchymal progenitor cell (MPC) recruitment, proliferation and differentiation that eventually results in bone regeneration. Prostaglandin E2 (PGE2) is an important regulator of bone metabolism and has an anabolic effect on fracture healing. Prior work from our laboratory showed EP1−/− mice have enhanced fracture healing, stronger cortical bones, higher trabecular bone volume and increased in vivo bone formation. We also showed that bone marrow MSCs from EP1−/− mice exhibit increased osteoblastic differentiation in vitro. In this study we investigate the changes in the periosteal derived MPCs (PDMPCs), which are crucial for fracture repair, upon EP1 deletion. EP1−/− PDMPCs exhibit increased numbers of total (CFU-F) and osteoblastic colonies (CFU-O) as well as enhanced osteoblastic and chondrogenic differentiation. Moreover, we tested the possible therapeutic application of a specific EP1 receptor antagonist to accelerate fracture repair. Our findings showed that EP1 antagonist administration to wild type mice in the early stages of repair similarly resulted in enhanced CFU-F, CFU-O, and osteoblast differentiation in PDMPCs and resulted in enhanced fracture callus formation at 10 days post fracture and increased bone volume and improved biomechanical healing of femur fractures at 21 days post fracture.
      PubDate: 2020-03-01
       
  • In Vivo Characterization of Poly(ethylene glycol) Hydrogels with
           Thio-β Esters
    • Abstract: Abstract Resorbable hydrogels have numerous potential applications in tissue engineering and drug delivery due to their highly tunable properties and soft tissue-like mechanical properties. The incorporation of esters into the backbone of poly(ethylene glycol) hydrogels has been used to develop libraries of hydrogels with tunable degradation rates. However, these synthetic strategies used to increase degradation rate often result in undesired changes in the hydrogel physical properties such as matrix modulus or swelling. In an effort to decouple degradation rate from other hydrogel properties, we inserted thio-β esters into the poly(ethylene glycol)-diacrylate backbone to introduce labile bonds without changing macromer molecular weight. This allowed the number of hydrolytically labile thio-β esters to be controlled through changing the ratios of this modified macromer to the original macromer without affecting network properties. The retention of hydrogel properties at different macromer ratios was confirmed by measuring gel fraction, swelling ratio, and compressive modulus. The tunable degradation profiles were characterized both in vitro and in vivo. Following confirmation of cytocompatibility after exposure to the hydrogel degradation products, the in vivo host response was evaluated in comparison to medical grade silicone. Collectively, this work demonstrates the utility and tunability of these hydrolytically degradable hydrogels for a wide variety of tissue engineering applications.
      PubDate: 2020-03-01
       
  • Evaluation of an Engineered Hybrid Matrix for Bone Regeneration via
           Endochondral Ossification
    • Abstract: Abstract Despite its regenerative ability, long and segmental bone defect repair remains a significant orthopedic challenge. Conventional tissue engineering efforts induce bone formation through intramembranous ossification (IO) which limits vascular formation and leads to poor bone regeneration. To overcome this challenge, a novel hybrid matrix comprised of a load-bearing polymer template and a gel phase is designed and assessed for bone regeneration. Our previous studies developed a synthetic ECM, hyaluronan (HA)–fibrin (FB), that is able to mimic cartilage-mediated bone formation in vitro. In this study, the well-characterized HA–FB hydrogel is combined with a biodegradable polymer template to form a hybrid matrix. In vitro evaluation of the matrix showed cartilage template formation, cell recruitment and recruited cell osteogenesis, essential stages in endochondral ossification. A transgenic reporter-mouse critical-defect model was used to evaluate the bone healing potential of the hybrid matrix in vivo. The results demonstrated host cell recruitment into the hybrid matrix that led to new bone formation and subsequent remodeling of the mineralization. Overall, the study developed and evaluated a novel load-bearing graft system for bone regeneration via endochondral ossification.
      PubDate: 2020-03-01
       
  • Improving the Osteogenicity of PCL Fiber Substrates by
           Surface-Immobilization of Bone Morphogenic Protein-2
    • Abstract: Abstract Polycaprolactone (PCL) fiber scaffolds are attractive, albeit inert, substrates for ligament regeneration, that may be improved by incorporating trophic factors to guide tissue remodeling in vivo. In particular, immobilization of bone morphogenic protein-2 (BMP-2) to the scaffold surface may facilitate rapid and robust integration of the scaffold with adjacent bone tissues. As a first step toward testing this, model PCL surfaces were modified by the addition of heparin (Hep) and BMP-2 to facilitate osteoblastic differentiation. Specifically, Hep was combined with PCL at 0, 0.5, and 1 wt% (denoted as PCL, PCL–0.5Hep, and PCL–1Hep), cast into films, and then BMP-2 was immobilized to surfaces by either adsorption and covalent conjugation. Here, BMP-2 concentration increased systematically with incorporation of Hep, and higher concentrations were achieved by covalent conjugation. Next, blends were electrospun to form thin meshes with fiber diameters of 0.92, 0.62, and 0.54 μm for PCL, PCL–0.5Hep, and PCL–1Hep, respectively. Mesenchymal stem cells (MSCs) had no difficulty attaching to and proliferating on all meshes. Lastly, PCL–1Hep meshes were prepared with adsorbed or covalently conjugated BMP-2 and cultured with MSCs in the absence of osteogenic factors. Under these conditions, alkaline phosphatase activity and deposition of bone sialoprotein, osteopontin, and calcium minerals—markers of osteoblastic differentiation—were significantly higher on surfaces with immobilized BMP-2. Together, these data indicate that covalent immobilization of trophic factors confers bioactivity to scaffolds, which may be applied in a spatially controlled manner for ligament regeneration and bone integration.
      PubDate: 2020-03-01
       
  • Design of an Adhesive Film-Based Microfluidic Device for Alginate
           Hydrogel-Based Cell Encapsulation
    • Abstract: Abstract To support the increasing translational use of transplanted cells, there is a need for high-throughput cell encapsulation technologies. Microfluidics is a particularly promising candidate technology to address this need, but conventional polydimethylsiloxane devices have encountered challenges that have limited their utility, including clogging, leaking, material swelling, high cost, and limited scalability. Here, we use a rapid prototyping approach incorporating patterned adhesive thin films to develop a reusable microfluidic device that can produce alginate hydrogel microbeads with high-throughput potential for microencapsulation applications. We show that beads formed in our device have high sphericity and monodispersity. We use the system to demonstrate effective cell encapsulation of mesenchymal stem cells and show that they can be maintained in culture for at least 28 days with no measurable reduction in viability. Our approach is highly scalable and will support diverse translational applications of microencapsulated cells.
      PubDate: 2020-03-01
       
  • Complete Myogenic Differentiation of Adipogenic Stem Cells Requires Both
           Biochemical and Mechanical Stimulation
    • Abstract: Abstract Vascular tissue engineering of the middle layer of natural arteries requires contractile smooth muscle cells (SMC) which can be differentiated from adipose-derived mesenchymal stem cells (ASC) by treatment with transforming growth factor-β, sphingosylphosphorylcholine and bone morphogenetic protein-4 (TSB). Since mechanical stimulation may support or replace TSB-driven differentiation, we investigated its effect plus TSB-treatment on SMC orientation and contractile protein expression. Tubular fibrin scaffolds with incorporated ASC or pre-differentiated SMC were exposed to pulsatile perfusion for 10 days with or without TSB. Statically incubated scaffolds served as controls. Pulsatile incubation resulted in collagen-I expression and orientation of either cell type circumferentially around the lumen as shown by alpha smooth muscle actin (αSMA), calponin and smoothelin staining as early, intermediate and late marker proteins. Semi-quantitative Westernblot analyses revealed strongly increased αSMA and calponin expression by either pulsatile (12.48-fold; p < 0.01 and 38.15-fold; p = 0.07) or static incubation plus TSB pre-treatment (8.91-fold; p < 0.05 and 37.69-fold; p < 0.05). In contrast, contractility and smoothelin expression required both mechanical and TSB stimulation since it was 2.57-fold increased (p < 0.05) only by combining pulsatile perfusion and TSB. Moreover, pre-differentiation of ASC prior to pulsatile perfusion was not necessary since it could not further increase the expression level of any marker.
      PubDate: 2020-03-01
       
  • Re-Differentiation of Human Meniscus Fibrochondrocytes Differs in
           Three-Dimensional Cell Aggregates and Decellularized Human Meniscus Matrix
           Scaffolds
    • Abstract: Abstract Decellularized matrix (DCM) derived from native tissues may be a promising supporting material to induce cellular differentiation by sequestered bioactive factors. However, no previous study has investigated the use of human meniscus-derived DCM to re-differentiate human meniscus fibrochondrocytes (MFCs) to form meniscus-like extracellular matrix (ECM). We expanded human MFCs and seeded them upon a cadaveric meniscus-derived DCM prepared by physical homogenization under hypoxia. To assess the bioactivity of the DCM, we used conditions with and without chondrogenic factor TGF-β3 and set up a cell pellet culture model as a biomaterial-free control. We found that the DCM supported chondrogenic re-differentiation and ECM formation of MFCs only in the presence of exogenous TGF-β3. Chondrogenic re-differentiation was more robust at the protein level in the pellet model as MFCs on the DCM appeared to favour a more proliferative phenotype. Interestingly, without growth factors, the DCM tended to promote expression of hypertrophic differentiation markers relative to the pellet model. Therefore, the human meniscus-derived DCM prepared by physical homogenization contained insufficient bioactive factors to induce appreciable ECM formation by human MFCs.
      PubDate: 2020-03-01
       
  • X-ray CT in Phase Contrast Enhancement Geometry of Alginate Microbeads in
           a Whole-Animal Model
    • Abstract: Abstract Imaging soft biomaterials in vivo is a significant challenge, as most conventional techniques are limited by biomaterial contrast, penetration depth, or spatial resolution. Exogeneous contrast agents used to increase contrast may also alter material properties or exhibit local toxicity. The capability to observe biomaterial constructs in vivo without introducing exogenous contrast would improve preclinical testing and evaluation. Conventional X-ray Computed Tomography allows fast, high-resolution imaging at high penetration depth, but biomaterial contrast is low. Previous studies employing X-ray phase contrast (XPC) and utilizing a synchrotron source provided support for the significant potential of XPC in imaging biomaterials without contrast agents. In this study, XPC tomography was used to image alginate hydrogel microspheres within a small animal omental pouch model using a commercially available X-ray source. Multilayer microbeads could be identified in the XPC images with volumetric and structural information not possible in histological analysis. The number of microbeads present and microbead volume and diameter could be quantified from the images. The results of this study show that XPC tomography can be a useful tool for monitoring of implanted soft biomaterials in small animal models.
      PubDate: 2020-03-01
       
  • Fetal Transcatheter Trileaflet Heart Valve Hemodynamics: Implications of
           Scaling on Valve Mechanics and Turbulence
    • Abstract: Abstract The scarcity of data available on the best approach for pulmonary fetal valve replacement or implantation necessitate an investigation on whether practices using adult transcatheter valves could be translated to fetal applications. The objective of this study is to evaluate the hemodynamic characteristics and the turbulent properties of a fetal sized trileaflet transcatheter pulmonary valve in comparison with an adult balloon-expandable valve in order to assess the possibility of designing valves for fetal applications using dynamic similarity. A 6 mm fetal trileaflet valve and a 26 mm SAPIEN 3 valve were assessed in a pulse duplicator. Particle image velocimetry was performed. Pressure gradient (ΔP), effective orifice area (EOA), regurgitant fractions (RF), pinwheeling indices (PI) and turbulent stresses were evaluated. ΔP was 8.56 ± 0.139 and 7.76 ± 0.083 mmHg with fetal valve and SAPIEN respectively (p < 0.0001); EOA was 0.10 ± 0.0007 and 2.1 ± 0.025 cm2 with fetal valve and SAPIEN respectively (p < 0.0001); RF with the fetal valve was 2.35 ± 1.99% and with SAPIEN 10.92 ± 0.11% (p < 0.0001); PI with fetal valve was 0.404 ± 0.01 and with SAPIEN 0.37 ± 0.07; The flow regime with the fetal valve was turbulent and Reynolds numbers reached about 7000 while those with the SAPIEN reached about 20,000 at peak velocity. Turbulent stresses were significantly higher with fetal valve compared with SAPIEN. Instantaneous viscous shear stresses with fetal valve were 5.8 times higher than those obtained with SAPIEN and Reynolds shear stresses were 2.5 times higher during peak systole. The fetal valve implantation leads to a turbulent flow (specific to this particular type and design of valve) regime unlike what is expected of a small valve with different flow properties compared to adult valves.
      PubDate: 2020-02-12
       
  • Fluid–Structure Interaction Models of Bioprosthetic Heart Valve Dynamics
           in an Experimental Pulse Duplicator
    • Abstract: Abstract Computer modeling and simulation is a powerful tool for assessing the performance of medical devices such as bioprosthetic heart valves (BHVs) that promises to accelerate device design and regulation. This study describes work to develop dynamic computer models of BHVs in the aortic test section of an experimental pulse-duplicator platform that is used in academia, industry, and regulatory agencies to assess BHV performance. These computational models are based on a hyperelastic finite element extension of the immersed boundary method for fluid–structure interaction (FSI). We focus on porcine tissue and bovine pericardial BHVs, which are commonly used in surgical valve replacement. We compare our numerical simulations to experimental data from two similar pulse duplicators, including a commercial ViVitro system and a custom platform related to the ViVitro pulse duplicator. Excellent agreement is demonstrated between the computational and experimental results for bulk flow rates, pressures, valve open areas, and the timing of valve opening and closure in conditions commonly used to assess BHV performance. In addition, reasonable agreement is demonstrated for quantitative measures of leaflet kinematics under these same conditions. This work represents a step towards the experimental validation of this FSI modeling platform for evaluating BHVs.
      PubDate: 2020-02-07
       
  • Core Competencies for Undergraduates in Bioengineering and Biomedical
           Engineering: Findings, Consequences, and Recommendations
    • Abstract: Abstract This paper provides a synopsis of discussions related to biomedical engineering core curricula that occurred at the Fourth BME Education Summit held at Case Western Reserve University in Cleveland, Ohio in May 2019. This summit was organized by the Council of Chairs of Bioengineering and Biomedical Engineering, and participants included over 300 faculty members from 100+ accredited undergraduate programs. This discussion focused on six key questions: QI: Is there a core curriculum, and if so, what are its components' QII: How does our purported core curriculum prepare students for careers, particularly in industry' QIII: How does design distinguish BME/BIOE graduates from other engineers' QIV: What is the state of engineering analysis and systems-level modeling in BME/BIOE curricula' QV: What is the role of data science in BME/BIOE undergraduate education' QVI: What core experimental skills are required for BME/BIOE undergrads' s. Indeed, BME/BIOI core curricula exists and has matured to emphasize interdisciplinary topics such as physiology, instrumentation, mechanics, computer programming, and mathematical modeling. Departments demonstrate their own identities by highlighting discipline-specific sub-specialties. In addition to technical competence, Industry partners most highly value our students’ capacity for problem solving and communication. As such, BME/BIOE curricula includes open-ended projects that address unmet patient and clinician needs as primary methods to prepare graduates for careers in industry. Culminating senior design experiences distinguish BME/BIOE graduates through their development of client-centered engineering solutions to healthcare problems. Finally, the overall BME/BIOE curriculum is not stagnant—it is clear that data science will become an ever-important element of our students’ training and that new methods to enhance student engagement will be of pedagogical importance as we embark on the next decade.
      PubDate: 2020-02-05
       
 
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