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The intention of these study was assess if the modified bacterial cellulose can be used as an artificial auricle skeleton. Introduction: The auricle is one part of the external ear. It consists of skin, cartilage muscles and adipose tissue, wherein the cartilage gives shape to the structure There are several indications for reconstruction, such as congenital anomalies, mechanical injuries and burns, and a range of methods have been proposed for complete reconstruction of the auricle. Matherial and methods: A bacterial cellulose membrane at least 25 mm in thickness was produced in vitro by Actobacter xylinum culture. The entire artificial human auricle skeleton was made to scale to allow its implantation into an animal model Wistar rats Forty rats were divided into four groups of 10 animals. Each group was assigned a different resection time: 14 days, 30 days, 90 days or 720 days. After each resection, an examination of the artificial skeleton and the tissues surrounding it was conducted. The surgical procedure was based on the Nagata technique Results: Resection after 14 , 30 , 90 and 720 days shows progression of healing process and integration of artificial skeleton in to the animal body. There are no signs of shape change and deterioration of the skeleton. Disscusion: Several surgical techniques and biotechnological methods have been developed over the past few years to improve the results of facial reconstruction. Other approaches can be used to create auricle cartilage which are based on scaffolds and chondrocytes. Conclusion: My findings indicate that modified bacterial cellulose can be used to form an effective artificial auricle which appears to maintain its shape and elasticity, with no signs of degradation being observed.

INTRODUCTION Peripheral 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 METHODS Polymer 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. RESULTS Motor 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. CONCLUSIONS Application 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.

Introduction The subject of the experiment was bacterial nanocellulose, a natural polymer produced by bacteria - Gluconacetobacter xylinus. Following a specific modification process a cartilage-like material for restoration of damaged tissues may be produced. The obtained implants with excellent biocompatibility, mouldability, biophysical and chemical properties perfectly fit the needs of reconstructive surgery. The goal of the experiment was to develop and analyze cellulosic guidance channels in vivo for the reconstruction of damaged peripheral nerves. Material and methods The experiments were conducted on Wistar rats, femoral nerve. Cellulose was produced according to a self-patented method. In the experimental group tubulization was applied, whereas in the control traditional end-to-end connection was used. Observation time was 30, 60, 90, and 180 days. Results evaluation included histological analysis and postoperative observation of motor recovery. Results The overgrowth of connective tissue and disorganisation of neural structures was evident in 86.67% of control specimens, while for cellulosic group it was only 35% (p = 0.0022). Tubulization prevented the excessive proliferation of connective tissue and isolated from penetration with scar tissue. Autocannibalism, being probably an evidence of neurotrophic factors amassment, was observed in cellulosic group but not in the control one. Motor recovery did not differ significantly (p > 0.05). Biocompatibility of implants was affirmed by very small level of tissue response and susceptibility to vascularisation. Conclusions Cellulosic neurotubes effectively prevent the formation of neuromas. They are of very good biocompatibility and allow the accumulation of neurotrophic factors inside, thus facilitating the process of nerve regeneration.

1-Methylnicotinamide (MNA) is a primary metabolite of nicotinamide recently proven to cause systemic increase in PGI(2) plasma levels in an unknown mechanism. Our present study was aimed at verifying whether the increased production of PGI(2), a vasodilating prostanoid, in response to MNA, its metabolite N-methyl-2-pyridone-5-carboxamide (Met2PY), and nicotinamide may be reproduced under in vitro conditions. Since prostacyclin is a vasodilating prostanoid, we also performed the functional tests in the ex vivo model of coronary vascular bed perfusion to evaluate the vasoactive properties of those compounds. We did not observe any significant effect of the tested drugs on either PGI(2) or PGE(2) secretion in our in vitro model. Nicotinamide at the concentrations of 10 and 100 μmol/l and 100 μmol/l Met2PY slightly but significantly increased coronary flow in rat heart. These increases, however, remained very low when compared to that induced by the reference compound, bradykinin (100 nmol/l). Perfusion of rat hearts with Met2PY in the presence of 50 μmol/l indomethacin resulted in decreased coronary flow, which proves that the effect is cyclooxygenase dependent. We conclude that MNA metabolites should be more carefully addressed in reference to pro-prostacyclin activity and that systemic mechanism of MNA-induced PGI(2) production needs further clarification.

UNLABELLED Modern methods of hernia tension free treatment use very wide range of modern biomaterials. Most of them are used transabdominal. For the best and most convenient treatment of large hernias would be a mesh suitable for intraperitoneal use with low adhesion ability to internal organs.THE AIM OF THE STUDY was to compare three types of intraperitoneal meshes. MATERIAL AND METHODS. The study compared three types of intraperitoneal meshes. Sub-chronic (14 days) and chronic (90 days) macro-and microscopic examination were performed on rats (n = 69). Properties of the polypropylene mesh (PLP), Dynamesh®-iPOM and polypropylene covered with chitosan (PLP+chitosan) were evaluated and compared. RESULTS. It has been shown that the test meshes differ slightly during the healing process. CONCLUSION The PLP+chitosan mesh had the best biocompatible features of them all.