Experimental research In vivo evaluation of nerve guidance channels of PTMC/PLLA porous biomaterial

Abstract

IntroductionPeripheral nerve disruptions, frequently occurring during limb injuries, give rise to serious complications of patients recovery resulting from limitations in neural tissue regeneration capabilities. To overcome this problem bridging techniques utilizing guidance channels gain their importance. Biodegradable polymeric tubes seem to be more prospective then non-degradable materials – no necessity of implant removal and possibilities of release of incorporated drugs or biologically active agents that may support nerve regeneration process are the main advantages.Material and methodsPolymer blend of commercial poly(L-lactic acid) (PLLA) and in-house synthesized poly(trimethylene carbonate) (PTMC) were processed in an organic solvent – phase inversion process on a supporting rod – to form a guidance porous tube of 1.1 mm inner diameter. In vivo experiments on rat's cut femoral nerve by using either the tubes or end-to-end suturing (control group) involved 22 and 19 rats, respectively. Motor recovery of operated limbs, neuroma occurrence and histopathology of explanted nerves were evaluated after 30, 60 and 90 days of implantation.ResultsMotor recovery of the limbs was of similar rate for the two animal groups. The neuroma formation was evident in over 90% control specimens, while for the bridging group it was less than 40% of all evaluable samples (p = 0.0022). Biocompatibility of applied materials was affirmed by moderate tissue response.ConclusionsApplication of the biodegradable PLLA/PTMC polymeric tubes effectively supports regeneration of discontinued nerves. The applied material prevents neuroma formation, by reducing the scar tissue formation time and, thus, accelerating the process of neural tissue restoration.

Assessment of Electrospun and Ultra-lightweight Polypropylene Meshes in the Sheep Model for Vaginal Surgery

“…UPy-PC is a thermoplastic elastomer with PC soft blocks and hard blocks composed of interacting and phase-separated hydrogen bonding units based on the 2-ureido-[1H]-pyrimidin-4-one (UPy) motif [11]. PC is a degradable polyester, which has been successfully used in nerve and bone regeneration guidance [12,13]. UPy-modified polymers have been designed to serve as drug delivery vehicles, for example, in a porcine myocardial infarction model [14] and in a modular approach as a bioactive elastomeric material for tissue engineering [15].…”

Monoether-Tagged Biodegradable Polycarbonate Preventing Platelet Adhesion and Demonstrating Vascular Cell Adhesion: A Promising Material for Resorbable Vascular Grafts and Stents

“…Many PTMC-based biomaterials have recently been investigated for applications in a broad range of implantable and/or resorbable devices. Chemically functionalized PTMC analogues with different pendant groups are derived from their corresponding cyclic monomers, demonstrating a diverse alteration of physicochemical properties. − However, most of these analogues have been designed to be used as solutions, such as in drug/gene delivery, hydrogels, and antimicrobials. − In contrast, composites of PTMC and copolymers, including trimethylene carbonate (TMC), have been studied for bulk applications such as scaffolds for bone, cartilage, and nerve regeneration. − In addition, applications in blood vessels and as vascular stents are a targeted area of PTMC-based materials because the inherent flexible property of PTMC is well-suited for the required task. − However, as with other hydrophobic biodegradable polymers that require concomitant administration of anticoagulants and antiplatelets for applications in blood-contacting devices, blood compatibility, and in particular the ability to suppress platelet adhesion, is indispensable for the PTMC-based materials. We have previously reported that no synthetic biodegradable polymers possessing high antithrombotic properties have been developed …”