Abstract: Materials, methods, and systems for biorthogonal ligation of hydrogel labels to crosslinked-natural polymer hydrogels are provided. A heterobifunctional linker includes a peptide-reactive activated functional group on the heterobifunctional linker, including an activated amine-reactive functional group, an activated thiol-reactive functional group and being reactive with a hydrogel comprising a crosslinked natural polymer. The heterobifunctional linker also includes a photocaged reactive group including a photocaged hydroxylamine, a photocaged alkoxyamine, a photocaged hydrazide, a photocaged amine, a photocaged tetrazine, or a photocaged alkyne-containing moiety. The peptide-reactive activated functional group does not include an azide.

Abstract: Systems, materials, and methods for making and using in vivo screening and highly parallel tissue grafting assay arrays are described. An implantable assay array may include a biocompatible substrate. The biocompatible substrate may define a number of mutually isolated microcompartments. The number of mutually isolated microcompartments may be determined based at least in part on a size of the implantable assay array. The size of the implantable assay array may be determined based at least in part on a size of an implantation subject.

Abstract: Substrates and methods for spatially resolved analyses of tissue samples are provided, allowing the data from such analyses to be mapped back to the tissue's initial architecture. For analyses that have previously been conducted on bulk, homogenized samples or on dissociated cell components not directly traceable to their prior positions in the tissue sample, spatial resolution of this data can allow better characterization of cell-cell and cell-microenvironment relationships and interactions. This spatial context can aid in determining structure-function relationships in healthy and diseased tissues may thereby enhance the scientific understanding of tissue homeostasis, development, disease, and repair. The information determined using the methods of the disclosure can also be applied to enhancing diagnostics evaluation of diseased tissues.

Abstract: The disclosure provides biocompatible heat exchangers, artificial tissues, systems, and thermofluidic methods for spatiotemporal control of biological signaling and gene expression. The disclosure demonstrates that in heat exchangers containing embedded cells with heat-activatable transgenes, gene expression patterning can be tuned both spatially and dynamically by varying channel network architecture, fluid temperature, fluid flow direction, and stimulation timing in a user-defined manner and maintained in vivo.

Abstract: A method and apparatus for reducing bleeding in biopsy procedures provides a cauterizing electrical current through an introducer needle as the needle is withdrawn. A majority of the length of the introducer needle may be insulated to concentrate the cauterization at its tip, and a field smoothing cauterizing stylet may be used in conjunction with the tube to provide more even cauterization and/or instrumentation to monitor cauterization. Cauterization may be controlled by the speed of withdrawal of the introducer needle as guided manually or automatically by the instrumentation.