Development of collagen scaffolds to address biomechanical design criteria for tendon–to–bone repair

The tendon-bone junction (TBJ) is a unique, mechanically dynamic and structurally graded anatomical zone which transmits tensile loads between tendon and bone. The TBJ repeatedly transmits high tensile loads to result in movement without failure by effectively dissipating stress concentrations which arise between mechanically dissimilar materials (tendon, bone). Upon injury, surgical repair techniques rely on mechanical fixation, and the local heterogeneities of the TBJ do not reform, causing poor functional outcomes (re-failure >90%). Biomaterial platforms and tissue engineering methods offer an alternative approach to address these injuries. Although current methods are moving towards multi-tissue regenerative approaches to address these injuries, it remains a challenge to fully characterize local mechanical and cellular heterogeneities within a single biomaterial using traditional techniques. Herein we describe a variety of collagen biomaterials which incorporate local changes and patterns in composition to create multi-compartment and composite scaffolds for the purpose of orthopedic regeneration. We demonstrate that these biomaterials exhibit enhanced, locally tunable mechanical properties, and are capable of providing mesenchymal stem cells (MSCs) signals in a spatially selective manner. We highlight tradeoffs and synergies in local cellular and mechanical behavior, which give rise to the mechanisms behind observed differences in bulk cellular and biomaterial behavior. This work provides key insights into design elements under consideration for mechanically competent, multi-tissue biomaterial platforms which drive MSCs towards spatially distinct lineages for orthopedic regeneration

Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

Development of collagen scaffolds to address biomechanical design criteria for tendon–to–bone repair

The tendon-bone junction (TBJ) is a unique, mechanically dynamic and structurally graded anatomical zone which transmits tensile loads between tendon and bone. The TBJ repeatedly transmits high tensile loads to result in movement without failure by effectively dissipating stress concentrations which arise between mechanically dissimilar materials (tendon, bone). Upon injury, surgical repair techniques rely on mechanical fixation, and the local heterogeneities of the TBJ do not reform, causing poor functional outcomes (re-failure >90%). Biomaterial platforms and tissue engineering methods offer an alternative approach to address these injuries. Although current methods are moving towards multi-tissue regenerative approaches to address these injuries, it remains a challenge to fully characterize local mechanical and cellular heterogeneities within a single biomaterial using traditional techniques. Herein we describe a variety of collagen biomaterials which incorporate local changes and patterns in composition to create multi-compartment and composite scaffolds for the purpose of orthopedic regeneration. We demonstrate that these biomaterials exhibit enhanced, locally tunable mechanical properties, and are capable of providing mesenchymal stem cells (MSCs) signals in a spatially selective manner. We highlight tradeoffs and synergies in local cellular and mechanical behavior, which give rise to the mechanisms behind observed differences in bulk cellular and biomaterial behavior. This work provides key insights into design elements under consideration for mechanically competent, multi-tissue biomaterial platforms which drive MSCs towards spatially distinct lineages for orthopedic regeneration.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste