Hydrogel membranes based on genipin-cross-linked chitosan blends for corneal epithelium tissue engineering

Novel polymeric hydrogel scaffolds for corneal epithelium cell culturing based on blends of chitosan with some other biopolymers such as hydroxypropylcellulose, collagen and elastin crosslinked with genipin, a natural substance, were prepared. Physicochemical and biomechanical properties of these materials were determined. The in vitro cell culture experiments with corneal epithelium cells have indicated that a membrane prepared from chitosan–collagen blend (Ch–Col) provided the regular stratified growth of the epithelium cells, good surface covering and increased number of the cell layers. Ch–Col membranes are therefore the most promising material among those studied. The performance of Ch–Col membranes is comparable with that of the amniotic membrane which is currently recommended for clinical applications

Use of autologous epithelium transplantation on various scaffolds to cover tissue loss in oral cavity : long-term observation

Background The aim of this study was to investigate the application of mucous membrane keratinocyte cultures on amniotic membrane and on poly(L-lactic acid) (PLLA) Purasorb PL38 to cover tissue loss in the oral cavity. Developments in molecular biology techniques and tissue engineering allow the culturing and identification of cells that can be anchored in the wound to achieve integrity of the tissue. Transplantation of tissues obtained from the patient's own cells is superior to allogenous transplantation where there is a possibility of transfection, rejection and the need for long-term immunosuppression. Methods In 9 patients (15 procedures) keratinocytes cultured on amniotic membrane and PLLA were transplanted to cover antro-oral fistulas and bone loss after osteoradionecrosis. Results In all 6 patients with outlasting antro-oral fistulas, the defects were healed. In 3 patients with 5 cases of tissue loss after osteoradionecrosis, we obtained healing of the wound in only 1 case. Histological examination of the cultures indicated that cultured cells formed well-differentiated layers, very similar to the keratinocytes of mucous membranes, although those seeded on amniotic membrane formed a single layer of cells, while those seeded on the PLLA scaffold were arranged on 2 or more layers: these differences were shown to be statistically significant with a morphometric analysis. Conclusions Autologous transplants of epithelium cultured on amniotic membrane and PLLA constitute a new and effective way of covering nonhealing tissue loss in the oral cavity in chosen cases, using modern methods of tissue engineering. </jats:sec

Double vision in Parkinson’s Disease: a systematic review

Introduction. The prevalence of diplopia in Parkinson’s disease (PD) ranges from 10% to 30%. Diplopia is usually limited to specific situations such as reading and looking around, however, it can also be constant. The aim of this review, supplemented by two case studies, was to summarise current knowledge on the frequency, possible causes, differential diagnosis, pathophysiology and treatment approaches to double vision in PD patients.Methodology. An electronic search (PubMed, Scopus, Embase and Web of Science) to identify studies regarding diplopia in PD patients was performed in May 2020. The following search terms were used: Parkinson’s Disease and diplopia.Results. Five articles are included in this literature review. In the literature, the number of included patients with PD who presented with symptoms of diplopia varied from a single case report to 88 patients. Diplopia was usually intermittent and binocular. The most commonly reported type of diplopia was single object diplopia, and the second most common was complete diplopia. Risk factors contributing to developing diplopia were: older age, disease duration, disease severity, cognitive decline, presence of visual hallucinations, and higher levodopa equivalent dose. Results also showed that diplopia had a significant impact on quality of life. Possible comorbidities of diplopia include myasthenia gravis and vascular disease.Conclusion. Diplopia is relatively common in PD, but still understudied. The research shows that it has a clear impact on health-related quality of life and patient safety. The acute onset of diplopia should always result in tests to exclude other diseases. Tailored interventions should be developed, leading to improved patient safety, quality of life, and quality of care

Evolution or revolution in therapy of acquired corneal limbal stem insufficiency: Holoclar® – a new medicine containing corneal epithelium stem cells

Leczenie niewydolności rąbka rogówki wkroczyło w nowy etap. W terapii zastosowano komórki pochodzące z hodowli. Tkanka uzyskana w laboratorium zawiera komórki macierzyste nabłonka rogówki pozyskane ze strefy rąbkowej. Dzięki temu zastąpienie hodowanym nabłonkiem patologicznych tkanek zapewnia jego stałą odnowę, tak jak dzieje się to w warunkach fizjologicznych. Do inicjacji hodowli wystarczy zaledwie 2 mm2 rąbka rogówki; pobrane komórki wytwarzają prawidłowy wielowarstwowy nabłonek, który zawiera też pulę komórek macierzystych. Odległe obserwacje potwierdzają, że z zastosowaniem tej metody można trwale odtwarzać powierzchnię nabłonkową rogówki.Treatment of corneal limbal insufficiency has entered a new stage. The cells from the culture were used in the therapy. The tissue produced in the laboratory contains stem cells of the corneal epithelium obtained from the limbal zone. With this technology, replacing the pathological tissue with the cultured epithelium gives its constant renewal, as it happens under physiological conditions. Only 2 mm2 of the corneal limbus is needed to initiate the culture, the harvested cells produce a normal multilamellar, stratified epithelium, that also contains a population of stem cells. Long-term observations confirm that this method can permanently maintain the epithelial surface of the cornea

Corneal epithelial scaffolds based on chitosan membranes containing collagen and keratin

Novel biodegradable and resorbable polymeric membranes that can function as supports for corneal epithelial cells cultures were developed. The materials used to synthesize these supports are natural polymers (i.e., chitosan, collagen and keratin [7 and 17% w/w]). The membranes were crosslinked with a natural crosslinker, genipin. The physicochemical, mechanical, and biological properties of the membranes were determined. It was found that the addition of keratin results in the appearance of antibacterial properties against Escherichia coli and in increased elasticity of the membranes