Marek Kolodziejczyk

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.

Facile and durable antimicrobial finishing of cotton textiles using a silver salt and UV light

In this study, we present facile antimicrobial finishing of cotton textiles. Screen printing was used for surface-finishing of cotton using a printing paste containing silver nitrate. UVC irradiation was applied to convert silver nitrate into a color product, thus also changing the color of the textiles. The color, its strength and stability of samples, depend on absorbed UVC energy and the formula of the printing paste. Scanning electron microscopy with the energy dispersive X-ray spectrometry revealed formation of silver particles on cotton threads; X-ray diffraction analysis and the time-of-flight secondary ion mass spectrometry did not provide clear information on these products. Microbiological studies revealed that the samples inhibited proliferation of Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Washing fastness tests confirmed resistance of the samples to at least 50 washings. Additionally, the inhibition zones increased as the number of washing cycles increased, which is unique for such samples. This work also presents an approach to the design of antimicrobially finished workwear.

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.

Medical Devices Regulation

Bacterial nanocellulose (BNC), thanks to its properties, can be used for the production of a wide range of medical devices. Medical devices made from pure bacterial nanocellulose or in association with other substances or materials must meet certain legal requirements while placed onto the market. The legislation in force concerning medical devices aims to eliminate undesirable products and to ensure that only such products are on the market and in use that meet all of the European Union requirements. This chapter provides the necessary definition and classification of a medical device, essential requirements, conformity assessment procedures, obligation of manufacturers (authorized representatives), and other information related to these issues.

Medical and Cosmetic Applications of Bacterial NanoCellulose

Abstract Bacterial nanocellulose, a natural, chemically pure biopolymer produced by microorganisms, is being well recognized as a highly biocompatible material. It has been already successfully applied as wet wound dressing and cosmetic facial mask, but its internal uses as artificial vessels, heart valves, and hernia meshes have been also conducted. Specific modifications of BNC make possible production of cartilage-like substitutes of meniscus, auricular, and nasal concha or even tubes for nerves regeneration. The final products are similar to natural tissues, with biocompatibility, moldability, biophysical, and chemical properties fitting the needs of regenerative medicine. Some of these biotechnological products have been already subjected to intensive in vivo investigation; some others, such as porous scaffolds for tissue engineering, are still under development. Recently, a lot of attention has been put into drug delivery systems production based on bio-cellulose. Continually, microbial cellulose offers a large field for systematic research on its new biomedical applications.

Stable composite of bacterial nanocellulose and perforated polypropylene mesh for biomedical applications: BNC Based Composites for Biomedical Applications

The article presents the method of preparation of new, stable bacterial cellulose composites with perforated solid materials for biomedical applications, comprising reconstructive surgery of soft and hard tissues. The composites were obtained in specially designed bioreactors equipped with a set of perforated mesh stripes threaded vertically to the culture medium, ensuring perpendicular growth of bacterial nanocellulose synthesized by Komagataeibacter xylinus E25 in stationary culture. The developed biocomposites have been tested for stability and mechanical strength, as well as for their in vitro inflammatory responses shown as mast cell degranulation with N-acetyl-β-d-hexosaminidase release and mast cell adhesion. The obtained results indicate that the composites components are well integrated after the process of cultivation and purification. Bacterial nanocellulose does not negatively influence mechanical properties of the polypropylene porous mesh, preserving its tensile strength, elasticity, and load. Moreover, application of bacterial cellulose makes the composites less immunogenic as compared to polypropylene itself. Therefore, the composites have the great potential of application in medicine, and depending on the applied porous material, might be used either in hernioplasty (if porous hernia mesh is used), cranioplasty (if perforated metal or polymeric cranial implant is applied), or as a protective barrier in any application that requires biocompatibility or antiadhesive properties improvement.