In vivo biocompatibility assessment of (PTFE–PVDF–PP) terpolymer-based membrane with potential application for glaucoma treatment

The aim of the work was to evaluate the in vivo biological behaviour of polymeric membrane materials for glaucoma implants. The base material was biostable synthetic terpolymer (PTFE–PVDF–PP) with proved biocompability (PN-EN ISO 10993). The samples manufactured in the form a membrane were subjected to chemical and physical treatment to create an open pore system within the polymer matrix. As a porogenic phase biodegradable natrium alginate in a fibrous form was employed. The non-perforating deep sclerectomy technique was performed in a rabbit model. The clinical observations were made after 14 and 30 days. During the study clinical symptoms of a moderate degree were observed, and histopathological changes were typical for foreign body implantation. At the end stage of the study no significant difference in histopathological assessment was found between control and experimental group. Similarities observed in both groups and relatively mild histopathological changes in the tissue surrounding the implant indicate that the observed symptoms come from a deep scleral trauma caused by surgery, and not by the presence of the implant itself

Investigations on improvement of functionality of silicone ectoprostheses

Silikonowe protezy twarzy (epitezy, ektoprotezy, protezy zewnętrzne) stosowane są u pacjentów, którzy w wyniku zabiegu chirurgicznego, w ramach leczenia chorób nowotworowych, wad wrodzonych, urazu utracili tkanki miękkie i twarde w zakresie twarzoczaszki np. oko, ucho, nos. Rekonstrukcje protetyczne wykorzystuje się w przypadku, gdy metody chirurgii plastycznej są nieskuteczne lub nie mogą być zastosowane. Istnieją różne metody umocowania ektoprotez. Badania kliniczne i ankietowe wykazały, iż większość pacjentów w pierwszej kolejności wybierała kleje medyczne. Niestety kleje te charakteryzują się krótkim czasem trwałego przytwierdzenia protezy do miejsca ubytku. W pracy zbadano przyczepności trzech rodzajów materiałów silikonowych przytwierdzanych do skóry pacjentów za pomocą klejów i taśm komercyjnych. W celu poprawy adhezji tworzywa zastosowano dwa rodzaje modyfikacji powierzchni. Zbadano wpływ obróbki mechanicznej na powierzchnie silikonów (gwarantujący wzrost chropowatości powierzchni). Zbadano także skuteczność chemicznej metody obróbki powierzchni (trawienie tworzywa w roztworach kwasów nieorganicznych). Celem weryfikacji skuteczności zastosowanych metod modyfikujących powierzchnię opracowano metodę pomiaru adhezji pomiędzy materiałem polimerowym a badanym środkiem klejącym (taśma, klej) wykorzystując w tym celu układ uchwytów uniwersalnej maszyny wytrzymałościowej.Silicone facial prostheses (epitheses, ecto-prostheses, external prostheses) are applied for patients who lost soft and hard tissues in craniofacial area, e. g. eye, ear, nose, due to a surgical treatment; tumour diseases treatment; birth defects or injuries. Prosthetic reconstructions are used when plastic surgery methods are ineffective, or cannot be applied. There are various methods of the ecto-prostheses fastening. Clinical tests and surveys revealed that the first choice for the majority of patients is medical glues. However, such glues can provide only short-time fastening of prosthesis to the damaged area. The work presents results of investigations on adhesion of three kinds of silicone materials fastened to patients' skin with the use of commercial glues and adhesive tapes. In order to improve the materials' adhesion two methods of their surface modification were applied. Influence of a mechanical treatment on the materials' surface was investigated. Effectiveness of the surface chemical treatment i.e. etching of the materials with inorganic acids solutions was investigated. In order to verify effectiveness of the applied surface modification methods a testing method of adhesion between the material and the adhesive agent i.e. adhesive tape or glue was developed. The testing method utilised a universal testing machine

Distribution of microelements in human articular cartilage : initial report

The aim of this study was evaluation of distribution microelements in human articular cartilage and to determine factors influencing it. The following elements were taken under consideration: Mg, Ca, Zn, Fe, Pb. Their concentration was assessed in the articular cartilage harvested from the loaded an unloaded area of human femoral heads. Initial results indicate that mechanical loadings are one of the important factors influencing distribution of microelements in human articular cartilage

Vibrational spectroscopy investigation of montmorillonite - chitosane nanocomposite materials

Biomaterials basing on natural polysaccharides, i.e. hiauronic acid, alginate, chitosane are an alternative for already applied bioresorbable synthetic materials basing on synthetic polyhydroxyacids. Their main advantages are good accessibility, low cost, easy forming and high biocompatibility. Additionally, they are a perfect matrix for bioactive nanoparticles i.e. hydroxyapatite (HAp), tricalcium phosphate (TCP) and silica (SiO2). The work presents results of research on nanocomposite consisting of chitosane matrix (CS) modified with a nanofiller, which was natural montmorillonite (MMT). Nanocomposite foils were produced by the casting method. In order to induce better biocompatibility, the surface of the CS/MMT composite was neutralized (bath in NaOH solution). The nanocomposite foils were subjected to a bioactivity test by incubation in SBF at 37oC for 7 days. It was observed that the CS/MMT material surface showed a local supersaturation, which was a result of apatite nucleation. The CS/MMT nanocomposites were investigated using FT-IR (Fourier Transform Infrared Spectroscopy) and Fourier Raman Spectroscopy. FTIR measurements of the samples were carried out on the transmission and reflection modes. The FTIR microscopy spectra were collected using Bio-Rad Excalibur with ATR attachment as well as microscope UMA500 equipped with MCT detector. Spectra were measured at 4 cm-1 resolution in the region from 4000 cm-1 to 600 cm-1. FT-Raman spectra were obtained using a FTS6000 Bio-Rad spectrometer with Ge detector. The samples were excited with a Nd-YAG laser (1064nm). Additional all materials in all steps experiments were observed under Scanning Electron Microscopy (Nova NanoSEM). Vibrational spectroscopy methods (FT Raman and FTIR) can be used for investigation of nanocomposite foils basing on biopolymers. High sensitivity the applied spectroscopy techniques show that in the result of the neutralization of CS/MMT foil (via incubation in NaOH solution) the biopolymer chain breaks. This phenomena is visible by intensity ratio between COC/ COH bands. Increase of reactivity of chitosane chain lead to entrapment of PO43-, which is the origin of the apatite forms nucleation process. Chemical treatment of the nanocomposite foils, i.e. NaOH washes influences their chemical structure and microstructure. Neutralisation of the foils is the first processing stage which precedes the potential use of CS/MMT foils in biomedical applications. The materials show a tendency to apatite crystallisation which may support regeneration of damaged bone tissue. The applied spectroscopic methods allowed to observe changes in the whole volume of the sample. Individual ATR measurements taken at various spectral ranges and penetration depths allow to observe subtle changes in the polymer matrix caused by chemical treatment (NaOH and SBF incubation). Results of the investigations indicate that in the CS/ MMT systems new chemical bonds and related to them vibrations appear. Quantity and quality of the interactions is related to characteristics of the nanoparticle and the presence of forming apatite structures

Vibrational spectroscopy investigation of montmorillonite-chitosane nanocomposite materials

Biomaterials basing on natural polysaccharides, i.e. hiauronic acid, alginate, chitosane are an alternative for already applied bioresorbable synthetic materials basing on synthetic polyhydroxy acids. Their main advantages are good accessibility, low cost, easy forming and high biocompatibility. Additionally , they are a perfect matrix for bioactive nanoparticles i.e. hydroxy apatite (HAp), tricalcium phosphate (TCP) and silica (SiO2). The work presents results of research on nanocomposite consisting of chitosane matrix (CS) modified with a nanofiller, which was natural montmorillonite (MMT). Nanocomposite foils were produced by the casting method. In order to induce better biocompatibility, the surface of the CS/MMT composite was neutralized (bath in NaOH solution). The nanocomposite foils were subjected to a bioactivity test by incubation in SBF at 37oC for 7 days. It was observed that the CS/ MMT material surface showed a local supersaturation, which was a result of apatite nucleation. The CS/ MMT nanocomposites were investigated using FT-IR ( Fourier Transform Infrared Spectroscopy) and Fourier Raman Spectroscopy. FTIR measurements o f the samples were carried out on the transmission and reflection modes. The FTIR microscopy spectra were collected using BioRad Excalibur with ATR attachment as well as microscope UMA500 equipped with MCT detector. Spectra were measure at 4 cm -1 resolution in the region from 4 000 cm -1 to 600 cm -1 . FT-Raman spectra were obtained using a FTS 6000 Bio-Rad spectrometer with Ge detector. The samples were excited with a Nd-YAG laser (1064nm). Additional all materials in all steps experiments were observed under Scanning Electron Microscopy (Nova Nano SEM). Vibrational spectroscopy methods (FT Raman and FTIR) can be used for investigation of nanocomposite foils basing on biopolymers. High sensitivity the applied spectroscopy techniques show that in the result of the neutralization of CS/ MMT foil (via incubation in NaOH solution the biopolymer chain breaks. This phenomena is visible by intensity ratio between COC/COH bands. Increase of reactivity of chitosane chain lead to entrapment of PO4+3-, which is the origin of the apatite forms nucleation process. Chemical treatment of the nanocomposite foils, i.e. NaOH washes in fluences their chemical structure and microstructure. Neutralisation of the foils is the first processing stage which precedes the potential use o fCS/ MMT foils in biomedical applications. The materials show a tendency to apatite crystallisation which may support regeneration of damaged bone tissue. The applied spectroscopic methods allowed to observe changes in the whole volume of the sample. Individual ATR measurements taken at various spectral ranges and penetration depths allow to observe subtle changes in the polymer matrix caused by chemical treatment (NaOH and SBF incubation). Results of the investigations indicate that in the CS/ MMT systems new chemical bonds and related to them vibrations appear. Quantity and quality of the interact ions is related to characteristics of the nanoparticle and the presence of forming apatite structures