Bartlomiej Grobelski

Modified bacterial cellulose tubes for regeneration of damaged peripheral nerves

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.

New methods Modified bacterial cellulose tubes for regeneration of damaged peripheral nerves

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.

Biocompatibility of Modified Bionanocellulose and Porous Poly(ϵ-caprolactone) Biomaterials

Biocompatibility of modified bionanocellulose (BC) and porous poly(ϵ caprolactone) (PCL) were compared to UHMWPE. For all the materials lack of cytotoxic effect to mouse fibroblasts was observed in vitro. In vivo study, subcutaneous implantations in Wistar rats, lasted for seven, 14, and 30 days. Subsequently the composition of surrounding tissue and explants surface changes was evaluated. No symptoms of acute inflammation were observed. Surrounding tissue thickness, the number of granulocytes, lymphocytes, macrophages, and blood vessels differed in time and revealed regular healing process. It is concluded that investigated PCL and BC are the materials with superior biocompatibility with high application potential.

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

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 rats 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.

There is no Smoke Without a Fire - Surgical Smoke and The Risk Connected with It

Starting from October 1-st, 1926, when Dr. Harvey Cushing was the first to apply electrocoagulation, the pioneer invention of Wiliam Bovie (1), surgical smoke has become an integral component of the atmosphere of the operating room. Thanks to technological progress in the twentieth century it was possible to use a laser or harmonic knife in the field of surgery. Undoubtedly, this facilitated the performance of selected procedures, but also exposed the operating room personnel to the effects of novel gases. In recent years, numerous investigations were undertaken, aimed at determining whether there was any risk associated with the exposure of patients and medical personnel to surgical smoke. Some of these studies showed the presence of elevated levels of potentially harmful substances, while others the transmission of an infection. It would seem that these facts should be alarming, considering that surgical smoke is far from being indifferent. What really speaks to ones imagination is the very common in literature data comparison of surgical smoke inhalation resulting from the cauterization of 1 g of tissue and smoking of 6 cigarettes (2, 3). Nevertheless, many doctors are not aware of the potential threat, considering smoke to be totally harmless (4). They argue for the above-mentioned with the lack of disease symptoms, despite many years of exposure. The aim of this study was to present the proven and theoretical risk posed by surgical smoke, as well as discuss methods which minimize this exposure.

Evaluation of surgical glove perforation after laparoscopic and open cholecystectomy.

Abstract Background : Surgical gloves provide a protective barrier against blood-born pathogens. Studies reveal glove perforation rates of up to 45%, which are often unrecognized by the surgeon or nurse. The goal of this study was to evaluate how often glove perforation occurs after laparoscopic and open cholecystectomy. Methods : Gloves from the operating surgeon and the first assistant were collected after operation and tested immediately using two methods : 1. Water leak test - the approved standardized method to detect holes after filling up the gloves with 1000ml of water. 2. Electrical resistance test - method to detect gloves conductivity immersed in saline bath. Results : Altogether, 376 gloves were studied. The overall perforation rate was 8%. Perforations more frequently were observed after laparoscopic than open cholecystectomy. The gloves worn by the operator were more likely to be perforated than those worn by the assistant surgeon in both types of operations. The most common site of perforation was in the index finger of the non-dominant hand. Thirty percent of gloves conducted electrical current, while 22% of them had no macroscopic evidence of perforation. Conclusion : Many of gloves might have microperforations that can not be detected using water leak test.

Properties comparison of intraperitoneal hernia meshes in reconstruction of the abdominal wall: animal model study.

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.

Surgical Gloves – Do they Really Protect Us?

* These authors contributed equally to the manuscript preparation The history of gloves in medicine dates back to more than 250 years. Their first use dates back to 1758, being attributed to the German doctor Johann Walbaum. His gloves were made of sheep cecum and used during the gynecological examination. The above-mentioned facilitated the introduction of the hand into the vagina, protecting from mechanical damage during obstetric procedures (1). At the end of the 17-th century the Austrian dermatologist, Joseph Plenk, suggested that midwives use protective gloves when performing vaginal examinations in patients infected with syphilis (2). A milestone was made in February, 1839. As a popular anecdote says, Charles Goodyear stumbled and poured on the fireplace, a solution of gum with sulfur, accidentally vulcanizing it. The material gained new properties and thus, applications. It seems to be impossible to determine who was the first to routinely use rubber gloves during surgery, but William Haldsted was considered as their first propagator (Head of the Department of Surgery, John Hopkins Hospital). In 1889, a scrub nurseCaroline Hampton developed severe eczema of the hands, due to chronic exposure to sublimate (mercuric chloride) and carbolic acid used for the disinfection of the hands. Attempts to apply protective collodium to the hands failed, since every flexion of the fingers tore the cellulose layer. During the visit to the prosectorium, Haldsted noticed that his friend William Welch, an anatomopathologist, wore a pair of clumsy looking rubber gloves. As it turned out the above-mentioned gloves protected his hands from the cadaverous smell, such hated by his wife. After such an observation, Haldsted asked the Goodyear Rubber Company to create a pair of rubber gloves for his nurse. The product proved to be so successful that the eczema healed and all surgeons began to use protective gloves. In June, 1890 roku miss Hampton became Mrs. Haldsted. Furthermore, another surgeon working at the hospital (Joseph Colt Bloodgood MD) noticed that the number of infections after hernia surgery significantly decreased when gloves were used (3, 4). The first study concerning the use of surgical rubber gloves was published in the zentralblatt fur Chirurgie in 1897, by the Estonian surgeon Werner von Manteuffel. As the Author wrote: „To wear boiled gloves is like to operate with boiled hands” (1). It is worth mentioning the merits of Jan Mikulicz-Radecki, a Polish surgeon from Wroclaw, who apart from wearing a surgical mask was the first to introduce silk gloves during surgical procedures (5).