Agnieszka Komisarczyk

The impact of the dibutyrylchitin molar mass on the bioactive properties of dressings used to treat soft tissue wounds

In this work, we describe a novel technique for producing biocompatible medical products with bioactive properties from the biodegradable polymer dibutyrylchitin (DBC). Materials produced by blowing out polymer solutions have excellent hemostaic properties and are easy to handle during surgery. Biocompatibility studies, encompassing hemostasis and the evaluation of post-implantation reactions, indicate that the biological properties of DBC depend on the molecular mass of the polymer. Lower molecular mass polymers are preferable for use in implanted wound dressings.

Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity

The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide), (PLGA), and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate) (PLGA/PHB). The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

Visualisation of liquid flow phenomena in textiles applied as a wound dressing

Abstract The aim of this work was to visualise liquid transport in textiles. Knowledge of the transport phenomena allows for the design of textiles for various applications, e.g., comfortable to wear filtration and wound dressing. To visualise liquid transport through textiles, three test methods were explored. The first one was the high spatial resolution magnetic resonance imaging (MRI) technique (also referred to as nuclear magnetic resonance (NMR) microscopy). It allowed the observation of the pathways of liquid flow through textiles. In the second method, a thermographic camera was used to record temperature changes and assess the liquid flow in the textile. The third method was using a high-speed video camera to observe the liquid transport within the textile. Two types of textiles were studied: a double-layer knitted fabric and a woven fabric, both made from hydrophilic and hydrophobic fibres (cotton, viscose and polypropylene). The knitted fabrics were tested as a new type of wound dressing, which trans

Biological Properties of Low-Toxicity PLGA and PLGA/PHB Fibrous Nanocomposite Implants for Osseous Tissue Regeneration. Part I: Evaluation of Potential Biotoxicity

In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(l-lactide-co-glycolide) (PLGA) and syntheticpoly([R,S]-3-hydroxybutyrate), PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and l-lactide (PLGA) was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc)4 as an initiator. The prototypes of the implants are composed of three layers of PLGA or PLGA/PHB, nonwoven fabrics with a pore structure designed to provide the best conditions for the cell proliferation. The bioactivity of the proposed implants has been imparted by introducing a hydroxyapatite material and IGF1, a growth factor. The developed prototypes of implants have been subjected to a set of in vitro and in vivobiocompatibility tests: in vitro cytotoxic effect, in vitro genotoxicity and systemic toxicity. Rabbitsshowed no signs of negative reactionafter implantation of the experimental implant prototypes.

Effects of electrospun scaffolds of di-O-butyrylchitin and poly-(ε-caprolactone) on wound healing

Background We sought to determine the usefulness of electrospun dibutyrylchitin (DBC) or poly-([Latin Small Letter Open E]-caprolactone [PCL]), in wound treatment. We investigated the mechanisms of action of these polymers on wound healing. Methods We synthesized DBC, a newly identified ester derivative of chitin, using a patented method comprising the substitution of butyryl groups at positions C-3 and C-6 in chitin molecules. We confirmed the double substitution by the butyric groups using infrared spectrometry. The fibrous scaffolds were obtained using the electrospinning method. A polypropylene net was implanted subcutaneously in the rat and served as a wound model. Results Both DBC and PCL increased granulation tissue weight in the wound. In contrast to PCL, DBC did not abolish glycosaminoglycan changes in wounds. The tested samples did not impair total collagen synthesis or induce excessive fibrosis. In both PCL- and DBC-treated wounds, we observed a lower level of soluble collagen (compared with controls). The results show better hydration of the wounds in both the DBC and PCL groups. No induction of large edema formation by the tested materials was observed. These polymers induced almost identical macrophage-mediated reactions to foreign-body implantation. The implants increased the blood vessel number in a wound. Conclusion Both PCL and DBC could be used as scaffolds or dressings for wound treatment. The materials were safe and well tolerated by animals. As DBC did not disturb glycosaminoglycan accumulation in wounds and absorbed twice as much liquid as PCL, it can be considered superior.

Plasma modification of polylactide nonwovens for dressing and sanitary applications

Polylactide (PLA) non-woven surfaces were modified with Radio Frequency plasma (RF) under reduced pressure with the use of two media, air and C6F14 vapor. The effectiveness of the plasma modification of nonwovens was analyzed by examining the fiber surface layer with ATR-FTIR absorption spectroscopy, SEM/EDX microanalysis of atomic composition, SEM surface morphology, wettability tests, susceptibility to water, and physiological liquid absorption tests and air permeability tests. The type of plasma used determines the effect obtained. Air plasma improves sorption properties of nonwovens and does not significantly affect air permeability. C6F14 vapor plasma significantly reduces the absorption of liquids by the fabric and increases its hydrophobicity. The effects obtained from the plasma are stable for six months of fabrics storage after treatment. PLA fabrics modified with plasma can be used for various applications such as dressing and sanitary materials.

Producing a poly(N,N-dimethylaminoethyl methacrylate) nonwoven by using the blowing out method

A poly(N,N-dimethylaminoethyl methacrylate) nonwoven was produced by the blowing out technique. The basic structural and mechanical properties of the obtained material were measured and described. It was found that the formed nonwoven has a smooth and delicate structure with quite weak mechanical properties. Its antibacterial properties against Staphylococcus aureus and Escherichia coli bacteria were shown. Some medical applications were suggested.

Natural and Safe Dyeing of Curing Clothing Intended for Patients with Dermatoses

1Department of Innovative Textile Technologies, Institute of Natural Fibres and Medicinal Plants, Poznań Director of Institute: Robert Sobków, PhD 2Marko-Kolor Co., Łódź Members of the Management Board: Wiesław Gajda, Longin Frączkiewicz and Andrzej Katryński 3Department of Material and Commodity Sciences and Textile Metrology, University of Technology, Łódź Head of Department: Professor Izabella Krucińska, MD, PhD 4Department of Geriatrics and Gerontology, University of Medicinal Science, Poznań Head of Department: Mariola Pawlaczyk, MD, PhD

Fabrication of Pure Electrospun Materials from Hyaluronic Acid

The aim of the research was to develop optimal conditions for manufacturing materials based on hyaluronic acid by the electrospun method. The studies were composed of three stages: the process of selection of the optimal solvent (mixture of solvents), the molecular weight of hyaluronic acid, and the concentration of biopolymer in the spinning solution. The influence of variable parameters on the rheological properties of the spinning solutions and electrospinning trails was tested. Depending on the electrospinning regime applied, the fibers obtained were characterised by a diameter of the order of 20 to 400 nm. As a result of the development works presented, an optimal molecular weight of the polymer, its concentration and system of solvents were determined, together with process parameters, ensuring a stable electrospinning process and relatively homogeneous nanofibers. Additionally studies on the residues of solvents used during electrosun formation were done and parameters of drying of the final materials were examined. This approach (verification of the presence of organic solvent residue in the nanofibrous formed) is important for the suitability of nanofibres as scaffolds for regenerative medicine. This study provides an opportunity for the understanding and identification of process parameters, allowing for predictable manufacturing nanofibers based on natural biopolymers, which makes it tremendously beneficial in terms of customisation.