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The Coronavirus disease 2019 (COVID-19) pandemic has significantly impacted and devastated the world. As the infection spreads, the projected mortality and economic devastation are unprecedented. In particular, racial and ethnic minorities may be at a particular disadvantage as many already assume the status of a marginalized group. Black Americans have a long-standing history of disadvantage and are in a vulnerable position to experience the impact of this crisis and the myth of Black immunity to COVID-19 is detrimental to promoting and maintaining preventative measures. We are the first to present the earliest available data in the peer-reviewed literature on the racial and ethnic distribution of COVID-19-confirmed cases and fatalities in the state of Connecticut. We also seek to explode the myth of Black immunity to the virus. Finally, we call for a National Commission on COVID-19 Racial and Ethnic Health Disparities to further explore and respond to the unique challenges that the crisis presents for Black and Brown communities.

Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges.

Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges.

Tissue engineering has been a highly successful strategy for regenerating individual musculoskeletal tissue types and holds great potential as a strategy for whole limb regeneration. In contrast to the bottom up approach of limb regeneration that relies on blastema formation outgrowth and cell dedifferentiation as seen in amphibians and lower vertebrates tissue engineering utilizes a top down approach that integrates material science cell and molecular biology and engineering. The aim of this research program is to take full advantage of this new direction to develop novel tissue engineering strategies for regenerating whole limbs in mammalian models. The tasks we have proposed use the collective expertise and insights of the group to test the hypothesis that functional organs can be regenerated by actively integrating the individual component tissues developed via the tissue engineering approach through the administration of appropriate environmental cues for limb regeneration. Key findings of this research program include the successful formation of both microsphere based nanofiber-based and composite microsphere-nanofiber structures for bone cartilage and ligament growth factor binding to and release from scaffolds cellular evaluation of marrow-derived mesenchymal and cell-specific cells on scaffolds in vivo visualization of vascularization of composite scaffolds and in vivo biocompatibility studies of scaffolds., The original document contains color images.

Rotating bioreactors have been used to overcome the limitations of passive nutrient diffusion in three-dimensional (3D) constructs for tissue engineering of bone. It is hypothesized that conventional scaffolds undergo repeated wall collisions in rotating bioreactors, which may disrupt bone tissue formation. In this study, we investigated the effects of wall collision on osteoblastic cells cultured on a microsphere based scaffold of varying densities in comparison to water. The conventional heavier than water (HTW; density > 1 g/cm3) scaffolds were fabricated by sintering HTW microspheres of 85:15 poly (lactide-co-glycolide) (PLAGA), and mixed scaffolds were designed by mixing lighter than water (LTW;density < 1 g/cm3) and HTW microspheres of PLAGA. We quantified average velocities of the two types of scaffolds using a particle tracking system, and no significant difference in average velocities was observed between the two types of scaffolds. however, HTW scaffolds have frequent wall collision and mixed scaffolds can avoid wall collision in bioreactors. When human Saos-2 osteoblast like cells were cultured on the scaffolds in bioreactors for 16 days, bone cell proliferation and cell differentiation on HTW scaffolds were significantly inhibited as compared to those cultured on mixed scaffolds in rotating bioreactors. These results indicate that collision between scaffolds and bioreactor wall is a confounding factor in osteoblastic cell proliferation and differentiation. These studies provide a foundation for development of 3D scaffolds for tissue engineering of bone in rotating bioreactors., Presented at the Nanoscale Materials Science in Biology and Medicine held in Boston, MA on 28 Nov-2 Dec 2004. Pub. in Materials Research Society Symposium Proceedings, v845 p333-338, 2005. ISBN 1-55-899-793-8. This article is from ADA434631 Materials Research Society Symposium Proceedings. Volume 845, 2005. Nanoscale Materials Science in Biology and Medicine, Held in Boston, MA on 28 November-2 December 2004

Three dimensional (3-D) scaffolds with appropriate mechanical properties play a significant role in scaffold-based tissue engineering. Chitosan, a natural polymer obtained from chitin, which forms a major component of crustacean exoskeleton, is a potential candidate for bone tissue engineering due to its excellent osteocompatibility and biodegradability. The aim of the present study is to develop 3-D porous chitosan scaffolds with mechanical properties in the range of trabecular bone as scaffolds for bone tissue engineering. Three dimensional scaffolds were prepared by sintering chitosan microspheres. Chitosan microspheres were prepared by ionotropic gelation of chitosan solution using sodium tripolyphosphate. It has been found that the microsphere size increased significantly with the increase of the concentration of chitosan solution. The microspheres were then sintered together using the synergetic effect of solvent and temperature. The compressive moduli of the 3-D sintered matrices were found to be in the mid range of trabecular bone. The osteocompatibility and osteoconductivity of the 3-D matrices were demonstrated by adhesion and proliferation of MC3T3-E1 osteoblast like cells on the matrices after 14 days in culture., Presented at the Nanoscale Materials Science in Biology and Medicine held in Boston, MA on 28 Nov-2 Dec 2004. Pub. in Materials Research Society Symposium Proceedings, v845 p187-192, 2005. ISBN 1-55-899-793-8. This article is from ADA434631 Materials Research Society Symposium Proceedings. Volume 845, 2005. Nanoscale Materials Science in Biology and Medicine, Held in Boston, MA on 28 November-2 December 2004

Polymer/ceramic composite matrices for bone tissue engineering were constructed by synthesizing a poorly crystalline calcium phosphate within poly(lactide-co-glycolide) microspheres that were subsequently fused together to form 3-dimensional structures. Calcium ion dissolution from the composite matrices in simulated body fluid was examined over a 24 hour period. The initial 4 hour period showed an increase in calcium ion concentration, whereas, a decrease in calcium ion concentration was noted thereafter. This decrease in concentration coincided with the precipitation of calcium phosphate on the surface of the matrices. Osteoblast proliferation studies on composite matrices showed statistically significant increases in cell number throughout the 21 day time period. These date together suggest that the composite matrix acts as both a calcium ion donor for reprecipitation of calcium phosphate that may enhance osteointegration of the implant, and a suitable surface for osteoblast proliferation., Presented at the Nanoscale Materials Science in Biology and Medicine held in Boston, MA on 28 Nov-2 Dec 2004. Pub. in Materials Research Society Symposium Proceedings, v845 p63-67, 2005. ISBN 1-55-899-793-8. This article is from ADA434631 Materials Research Society Symposium Proceedings. Volume 845, 2005. Nanoscale Materials Science in Biology and Medicine, Held in Boston, MA on 28 November-2 December 2004

Biodegradable polymeric nanofibers are of great interest as scaffolds for tissue engineering and drug delivery due to their extremely high surface area, high aspect ratio and similarity in structure to the extracellular matrix (ECM). Polyphosphazenes due to their synthetic flexibility, wide range of physico-chemical properties, non-toxic and neutral degradation products and excellent biocompatibility are suitable candidates for biomedical applications. The objective of the present study was to develop and evaluate composite nanofibers of a biodegradable polyphosphazene, polyBIS(ETHYL ALANATO)PHOSPHAZENE (PNEA) and nanocrystals of hydroxyapatite (nHAp) via electrospinning. A suspension of nHAp in dimethyl formamide (DMF) sonicated with PNEA solution in tetrahydrofuran (THF) was used to develop composite nanofiber matrices via electrospinning at ambient conditions. In the present study the theoretical loading of nHAp was varied from 50%-90% (w/w) to PNEA. The nHAp content (actual loading of nHAp) of the composite nanofibers was determined by gravimetric estimation. The composite nanofibers were characterized by transmission electron microscopy (TEM), gravimetry and energy dispersive X-ray mapping. This study demonstrated the feasibility of developing novel composite nanofibers of biodegradable polyphosphazenes with more than 50% (w/w) loading of nHAp on and within the nanofibers., Presented at the Nanoscale Materials Science in Biology and Medicine held in Boston, MA on 28 Nov-2 Dec 2004. Pub. in Materials Research Society Symposium Proceedings, v845 p91-96, 2005. ISBN 1-55-899-793-8. This article is from ADA434631 Materials Research Society Symposium Proceedings. Volume 845, 2005. Nanoscale Materials Science in Biology and Medicine, Held in Boston, MA on 28 November-2 December 2004

Hydroxyapatite formed from low temperature setting calcium phosphate cements (CPC) are currently been used for various orthopaedic applications. CPCs are attractive candidates for the development of scaffolds for bone tissue engineering, since they are moldable, resorbable, set at physiological temperature without the use of toxic chemicals, and can be processed in an operating room setting. However they may have mechanical disadvantages which seriously limit them to non-load bearing orthopaedic applications, The aim of the present study was to develop composites from ployphosphazenes and calcium deficient hydroxyapatite precursors to form poorly crystalline hydroxyapatite-polymer composites. Composites were formed from calcium deficient hydroxyapatite precursors (Ca/P - 1.5, 1.6) and biodegradable polyphosphazenes, polyBIS(ETHYL ALANATO)PHOSPHAZENE (PNEA50mPh50) at physiological temperature. The results demonstrated that poorly crystalline hydroxyapatite that resembled the mineral component of bone was formed in the presence of biodegradable polyphosphazenes. The surface morphology of all the four composites was identical with a porous microstructure. The composites supported the adhesion and proliferation of osteoblast like MC3T3-E1 cells making them potential candidates for bone tissue engineering., Presented at the Nanoscale Materials Science in Biology and Medicine held in Boston, MA on 28 Nov-2 Dec 2004. Pub. in Materials Research Society Symposium Proceedings, v845 p291-296, 2005. ISBN 1-55-899-793-8. This article is from ADA434631 Materials Research Society Symposium Proceedings. Volume 845, 2005. Nanoscale Materials Science in Biology and Medicine, Held in Boston, MA on 28 November-2 December 2004

The limitations of current grafting materials have driven the search for synthetic alternatives to cancellous bone. A variety of biodegradable polymer foams composed of poly(lactide-co-glycolide) PLAGA have been evaluated for such uses. However, structural limitations may restrict the clinical use of these scaffolds. We have developed a sintered microsphere scaffold composed of 85:15 poly(lactide-co-glycolide) with a biommetic pore system equivalent to the structure of cancellous bone. Analysis of the structural data, indicated that the microsphere matrix sintered at a temperature of 160 degrees C with a microsphere diameter of 355-425 micrometer resulted in a optimal, biomimetic structure with an approximate pore diameter of 75 to 275 micrometer, 35% porosity, and compressive modulus of 272 MPa. The in vitro evaluation of human osteoblasts on the sintered matrix indicated that the structure was capable of supporting the attachment and proliferation of the cells throughout its pore system. Immunofluorescent staining of actin showed that the cells were proliferating 3-dimensionally through the pore system. The stain for osteocalcin showed that the cells had maintained the phenotypic expression for this bone specific protein. Through this work, it was shown that an osteoconductive PLAGA scaffold with a pore system equivalent to the structure of cancellous bone could be fabricated through the sintered microsphere method., Papers from 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Oct 25-28, 2001, held in Istanbul, Turkey. See also ADM001351 for entire conference on cd-rom.