Microporous Biodegradable Films Promote Therapeutic Angiogenesis

Abstract

Peripheral arterial disease and critical limb ischemia are common symptoms of cardiovascular disease. Vascular surgery is used to create a bypass around occluded blood vessels to improve blood flow to ischemic muscle, thus avoiding the need for amputation. Attempts to vascularize tissues by therapeutic angiogenesis using delivery of exogenous angiogenic agents are underwhelming. A material‐based approach that provides an endogenous stimulus capable of promoting angiogenesis and increased tissue perfusion would provide a paradigm shift in treatment options available. It is reported here that microporous biodegradable films produced using thermally induced phase separation provide a localized biophysical stimulus of proangiogenic genes in vivo that is associated with increased blood vessel density and restoration of blood flow to ischemic tissue. These findings show, for the first time, that acellular, nonfunctionalized biodegradable biomaterials can provide an innovative, material‐based approach for therapeutic angiogenesis to enhance tissue reperfusion in vivo.

Large-Scale Fabrication of Freestanding Polymer Ultrathin Porous Membranes for Transparent Transwell Coculture Systems

“…In coculture systems, ultrathin and nanoscale porous PUP membranes enable cellular interactions while acting as both a physical barrier between the two cell types and a substrate for cell sheet formation. Previous studies have reported the hydrolytic degradation of PLA and its composites in vitro ; however, the degradation rate of biodegradable polymer scaffolds is influenced by various factors, including environmental conditions and material shape. , For cell coculture systems, the porous membrane is clearly intended to be nondegradable. To alleviate this concern, we investigated the in vitro degradation of PUP membranes in phosphate-buffered saline (PBS) solution with a pH of 7.4 at 37 °C for 2 weeks (Figure S7).…”

A facile approach to therapeutic angiogenesis using a platelet concentrate and microsphere composite

“…Evidence from our study supports the concept of engineering biomaterial interfaces to elicit biologically pertinent responses. We have recently demonstrated the proangiogenic secretome from MSCs is enhanced when cultured directly on textured films [ 22 ] and microspheres [ 23 ] prepared via TIPS. Here we demonstrate for the first time that the pro‐angiogenic secretome of platelet concentrates is significantly enhanced when mixed with TIPS textured microspheres.…”

Soft, Long‐Lived, Bioresorbable Electronic Surgical Mesh with Wireless Pressure Monitor and On‐Demand Drug Delivery

“…The porosity of the sponge (PLCL 160k) can be engineered via nonsolvent-induced phase separation technique (Figure S4, Supporting Information), which produced various sizes of micro-and nano-pores as shown in Figure 3c and Figure S5 (Supporting Information). [93][94][95][96] To investigate structural effects, the PPS configuration was compared with conventional structures: non-porous film (NPF) and non-porous pyramid film (NPPF) (Figures S6, Supporting Information). Mechano-electrical properties of the PPS in Figure 3d and Figure S7 (Supporting Information) show fractional changes in capacitance as a function of applied pressures; such highly porous structure can reach 50% of compressive strain just under 2 kPa, which allows for high sensitivity of 0.39 kPa −1 (NPPF: 0.07 kPa −1 ; NPF: 0.02 kPa −1 ).…”