Abstract: Compositions comprising polymeric networks comprising combinations of small molecule hair growth agents and natural products (e.g., vesicles, such as stem cell-derived exosomes) are described. The polymeric network can, for example, comprise keratin crosslinked via intermolecular disulfide bonds. Alternatively, the polymeric network can comprise keratin or a derivative thereof and another crosslinked hydrophilic polymer. Microneedles, microneedle arrays, and skin patches comprising the compositions are also described, as are methods of treating hair loss and/or promoting hair growth using the microneedles, microneedle arrays and/or skin patches.

Abstract: A composition comprising an amphiphilic polymeric material that is both hydrogen peroxide- and hypoxia-sensitive is described. The composition can further include a glucose-oxidizing enzyme and insulin, a bioactive derivative thereof, and/or another therapeutic agent (e.g., another diabetes treatment agent). The polymeric material can form vesicles that comprise single or multiple layers of the polymeric material that enclose the glucose-oxidizing enzyme and the insulin, bioactive derivative and/or other therapeutic agent. The vesicles can be loaded into microneedles to, for example, prepare microneedle arrays for skin patches. Methods of delivering insulin to a subject using the compositions, vesicles, microneedles, and/or microneedle array skin patches are also described.

Abstract: A closed-loop insulin delivery system is described. More particularly, the presently disclosed insulin delivery system can comprise glucose-responsive vesicles that release insulin in response to hypoxia triggered by enzymatic reduction of glucose. In addition or as an alternative to insulin, the delivery system can release other diabetes treatment agents, such as non-insulin-based diabetes treatment agents. The vesicles can be prepared from a hypoxia sensitive polymer, such as a hypoxia-sensitive hyaluronic acid (HS-HA). The HS-HA can comprise hydrophobic groups that can be reduced in hypoxic environments to form hydrophilic groups. The vesicles can be loaded into microneedles and microneedle array patches for use in the treatment of diabetes or to otherwise regulate blood glucose levels in subjects in need of such treatment.