In recent years, fibrin has been successfully used as a polymer drug delivery carrier. Passive properties of fibrin provide parenteral and local delivery of drug substances in controlled and prolonged manner and also tissue support, gluing and sealing. Fibrin also has hemostatic and proangiogenic effects. Discs, films, gels, beads and nanoparticles are among the most commonly proposed and used fibrin-based formulations. It is routinely obtained from fibrinogen and thrombin. Fibrin formulation methods are solution casting, dual syringe systems and emulsification. All fibrin formulations become gel after administration and water absorption. Biodegradation and biocompatibility are important advantages of fibrin, which make it possible to implant a formulation without the need to remove the carrier from the body after the drug is released. Fibrin-based drug delivery systems are proposed and applied in the treatment of wounds, infections and cancerous diseases.

In this work, we aimed to determine the role of the mechanical, structural, and thermal properties of poly(l-lactide-co-glycolide-co-trimethylene carbonate) (P(l-LA:GA:TMC)) with shape memory in the formulation of implantable and biodegradable rods with aripiprazole (ARP). Hot melt extrusion (HME) and electron beam (EB) irradiation were applied in the formulation process of blank rods and rods with ARP. Rod degradation was carried out in a PBS solution. HPLC; NMR; DSC; compression and tensile tests; molecular weight (Mn); water uptake (WU); and weight loss (WL) analyses; and SEM were used in this study. HME and EB irradiation did not influence the structure of ARP. The mechanical tests indicated that the rods may be safely implanted using a pre-filled syringe. During degradation, no unfavorable changes in terpolymer content were observed. A decrease in the glass transition temperature and the Mn, and an increase in the WU and the WL were revealed. The loading of ARP and EB irradiation induced earlier pore formation and more intense WU and WL changes. ARP was released in a tri-phasic model with the lag phase; therefore, the proposed formulation may be administered as a delayed-release system. EB irradiation was found to accelerate ARP release.

A significant deficit in the availability of human tissues has not resulted in less general interest in homogeneous heart valves. The application of homografts still remains the optimal solution in the surgical treatment of congenital and acquired defects. Obtaining the optimal properties of these valves is followed by processing, including sterilization. This method provides sterility with rewarding cell viability and maintenance of the tissues’ native features. The prepared material possesses appropriate properties at the level of structure and surface, which results in correct functioning in vivo. During the past several decades, sterilization conditions and the compositions of antibiotic mixtures have changed significantly. In this period, significant progress in the development of this method was achieved; however, in the last few years, various flaws in antibiotic sterilization of homografts have been revealed. The release of the antibiotic during microbiological tests of tissue evaluated for implantation or the possibility of side effects as a result of antibiotic release after implantation remain the most important issues here. In this work we characterized the main antibiotic mixtures that are currently in use.

Latanoprost (LTP) is a prostaglandin F2α analog used to lower intraocular pressure in glaucoma treatment administered daily as eye drops. In this study, a universal model based on poly(l-lactide-co-glycolide-co-trimethylene carbonate) with shape memory was proposed for the development of a solid biodegradable formulation with prolonged release administered intraconjunctivally, intravitreally, subconjunctivally, and subcutaneously. Solution casting and electron beam (EB) irradiation were applied to the matrix formulation. The properties of the native matrix and matrices degraded in a PBS buffer (pH 7.4) were monitored by NMR, DSC, GPC, and SEM. Water uptake (WU) and weight loss (WL) were also analyzed. LTP was released over 113 days in a tri-phasic and sigmoidal pattern without a burst effect and with a relatively long second release phase, in which changes were observed in the glass transition temperature, molecular weight (Mn), WU, and WL. EB irradiation decreased the initial Mn, increased WU, and accelerated LTP release with a shortened lag phase. This provides the opportunity to partially eliminate the use of drops at the start of treatment. SEM observations indicated that surface erosion is the prevalent degradation mechanism. The proposed model is an interesting solution during a preliminary study to develop final medicinal products that provide high adherence.