SummaryNanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using NanospiderTM technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct – the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.

Bacterial cellulose (BC) and poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels are both considered as biocompatible materials with potential use in various biomedical applications including cartilage, cardiovascular stent, and soft tissue engineering. In this work, the "ever-wet" process based on in situ UV radical polymerization of HEMA monomer in BC nanofibrous structure impregnated with HEMA was used, and a series of BC-PHEMA composites was prepared. The composite structures were characterized by ATR FT-IR spectroscopy, WAXD, SEM, and TEM techniques. The strategy of using densified BC material of various cellulose fiber contents was applied to improve mechanical properties. The mechanical properties were tested under tensile, dynamic shear, and relaxation modes. The final composites contained 1 to 20 wt% of BC; the effect of the reinforcement degree on morphology, swelling capacity, and mechanical properties was investigated. The biocompatibility test of BC-PHEMA composites was performed using mouse mesenchymal stem cells.

The addition of PEG of a particular MW enables to control CsA release from PLA nanofibrous carriers. The biological activity of CsA-loaded PLA nanofibers with PEG persists even after 144 h of previous extraction. Prepared materials are promising for local immunosuppression in various medical applications.

Niacin was the first hypolipidemic drug to significantly reduce both major cardiovascular events and mortality in patients with cardiovascular disease. Niacin favorably influences all lipoprotein classes, including lipoprotein [a],and belongs to the most potent hypolipidemic drugs for increasing HDL-C. Moreover, niacin causes favorable changes to the qualitative composition of lipoprotein HDL. In addition to its pronounced hypolipidemic action, niacin exerts many other, non-hypolipidemic effects (e.g., antioxidative, anti-inflammatory, antithrombotic), which favorably influence the development and progression of atherosclerosis. These effects are dependent on activation of the specific receptor HCA2. Recent results published by the two large clinical studies, AIM-HIGH and HPS2-THRIVE, have led to the impugnation of niacin's role in future clinical practice. However, due to several methodological flaws in the AIM-HIGH and HPS2-THRIVE studies, the pleiotropic effects of niacin now deserve thorough evaluation. This review summarizes the present and possible future use of niacin in clinical practice in light of its newly recognized pleiotropic effects.

Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using Nanospider TM technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct -the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.1939

Hyperlipidemia treatment based on niacin requires gastrointestinal administration of relatively high doses. The recommended dietary allowance of niacin as vitamin B3 is 14 to 16 mg daily in adults, while the doses of niacin used in the treatment of hyperlipidemia are generally in the range of 1 to 3 g. Administration of such large doses requires a high concentration of the active compound in the tablet and proper control of the drug release. In this study, a hydrogel matrix based on poly(2-hydroxyethyl methacrylate) and polyvinylpyrrolidone was investigated as delivery vehicle for controlled NA release into the gastrointestinal environment. The prepared hydrogel matrices varied in used monomer and crosslinker types and concentrations. The content of NA in tablets was between 65-80 %. The release profiles of NA from tablets were examined under three different pH values (1, 4.5 and 6.8) over the time period of 30 h. The effects of the monomer ratio, the crosslinking of the polymer network, and the solubility of niacin during drug release under various pH are discussed. The results showed that the release time period can be achieved in a relatively wide range of time and can be adjusted according to the medical requirements.

In order to create a soft tissue surplus, implantable volume expanders are often utilized in dental surgery. Implanted tissue expanders should gradually increase their volume, exerting a constant pressure on the surrounding tissue for weeks. Current tissue expanders are based predominantly on externally inflatable balloons or on osmotically active tissue expanders that use soft hydrogels wrapped in perforated plastic coatings, which limit fluid entry and swelling. We have designed and examined tissue expanders based on the controlled rate expansive hydrogels synthesized from copolymers of selected methacrylates and N-vinylpyrrolidone, cross-linked with a combination of non-degradable (glycol dimethacrylates) and hydrolytically degradable (N,O-dimethacryloylhydroxylamine) cross-linkers. These copolymers have close-to-linear volume expansion rates (up to 6-9 times their original volume) and exert an increasing swelling pressure in vitro. The anesthetic benzocaine has been incorporated into the hydrogels, and kinetic release experiments have shown that most of the drug (90%) was released within 48 h. Our proposed hydrogel expanders are homogeneous and have suitable mechanical properties, thus simplifying the surgical manipulations required. Further studies will be needed to completely evaluate their biocompatibility and tissue response to the implants.

Self-inflating soft tissue expanders represent a valuable modality in reconstructive surgery. For this purpose, particularly synthetic hydrogels that increase their volume by swelling in aqueous environment are used. The current challenge in the field is to deliver a material with a suitable protracted swelling response, ideally with an induction period (for sutured wound healing) followed by a linear increase in volume lasting several days for required tissue reconstruction. Here, we report on synthesis, swelling, thermal, mechanical and biological properties of novel hydrogel tissue expanders based on poly(styrene-alt-maleic anhydride) copolymers covalently crosslinked with p-divinylbenzene. The hydrogels exerted hydrolysis-driven swelling response with induction period over the first two days with minimal volume change and gradual volume growth within 30 days in buffered saline solution. Their final swollen volume reached more than 14 times the dry volume with little dependence on the crosslinker content. The mechanical coherence of samples during swelling and in their fully swollen state was excellent, the compression modulus of elasticity being between 750 and 850 kPa. In vitro cell culture experiments and in vivo evaluation in mice models showed excellent biocompatibility and suitable swelling responses meeting thus the application requirements as soft tissue expanders.