Poly(L-lactide-co-glycolide) thin films can act as autologous cell carriers for skin tissue engineering

Degradable aliphatic polyesters such as polylactides, polyglycolides and their copolymers are used in several biomedical and pharmaceutical applications. We analyzed the influence of poly(L-lactide-co-glycolide) (PLGA) thin films on the adhesion, proliferation, motility and differentiation of primary human skin keratinocytes and fibroblasts in the context of their potential use as cell carriers for skin tissue engineering. We did not observe visible differences in the morphology, focal contact appearance, or actin cytoskeleton organization of skin cells cultured on PLGA films compared to those cultured under control conditions. Moreover, we did not detect biologically significant differences in proliferative activity, migration parameters, level of differentiation, or expression of vinculin when the cells were cultured on PLGA films and tissue culture polystyrene. Our results indicate that PLGA films do not affect the basic functions of primary human skin keratinocytes and fibroblasts and thus show acceptable biocompatibility in vitro, paving the way for their use as biomaterials for skin tissue engineering

Electric field as a potential directional cue in homing of bone marrow-derived mesenchymal stem cells to cutaneous wounds

AbstractBone marrow-derived cells are thought to participate and enhance the healing process contributing to skin cells or releasing regulatory cytokines. Directional cell migration in a weak direct current electric field (DC-EF), known as electrotaxis, may be a way of cell recruitment to the wound site. Here we examined the influence of electric field on bone marrow adherent cells (BMACs) and its potential role as a factor attracting mesenchymal stem cells to cutaneous wounds. We observed that in an external EF, BMAC movement was accelerated and highly directed with distinction of two cell populations migrating toward opposite poles: mesenchymal stem cells migrated toward the cathode, whereas macrophages toward the anode. Analysis of intracellular pathways revealed that macrophage electrotaxis mostly depended on Rho family small GTPases and calcium ions, but interruption of PI3K and Arp2/3 had the most pronounced effect on electrotaxis of MSCs. However, in all cases we observed only a partial decrease in directionality of cell movement after inhibition of certain proteins. Additionally, although we noticed the accumulation of EGFR at the cathodal side of MSCs, it was not involved in electrotaxis. Moreover, the cell reaction to EF was very dynamic with first symptoms occurring within <1min. In conclusion, the physiological DC-EF may act as a factor positioning bone marrow cells within a wound bed and the opposite direction of MSC and macrophage movement did not result either from utilizing different signalling or redistribution of investigated cell surface receptors

Effects triggered by platinum nanoparticles on primary keratinocytes

The platinum (Pt)-group elements (PGEs) represent a new kind of environmental pollutant and a new hazard for human health. Since their introduction as vehicle-exhaust catalysts, their emissions into the environment have grown considerably compared with their low natural concentration in the earth crust. PGE emissions from vehicle catalysts can be also in the form of nanometer-sized particles (Pt nanoparticles [PtNPs]). These elements, both in their metallic form or as ions solubilized in biological media, are now recognized as potent allergens and sensitizers. Human skin is always exposed to toxic particles; therefore, in the present study we addressed the question of whether polyvinylpyrrolidone-coated PtNPs may have any negative effects on skin cells, including predominantly epidermal keratinocytes. In this study, PtNPs of two sizes were used: 5.8 nm and 57 nm, in concentrations of 6.25, 12.5, and 25 μg/mL. Both types of NPs were protected with polyvinylpyrrolidone. Primary keratinocytes were treated for 24 and 48 hours, then cytotoxicity, genotoxicity, morphology, metabolic activity, and changes in the activation of signaling pathways were investigated in PtNP-treated cells. We found that PtNPs trigger toxic effects on primary keratinocytes, decreasing cell metabolism, but these changes have no effects on cell viability or migration. Moreover, smaller NPs exhibited more deleterious effect on DNA stability than the big ones. Analyzing activation of caspases, we found changes in activity of caspase 9 and caspase 3/7 triggered mainly by smaller NPs. Changes were not so significant in the case of larger nanoparticles. Importantly, we found that PtNPs have antibacterial properties, as is the case with silver NPs (AgNPs). In comparison to our previous study regarding the effects of AgNPs on cell biology, we found that PtNPs do not exhibit such deleterious effects on primary keratinocytes as AgNPs and that they also can be used as potential antibacterial agents, especially in the treatment of Escherichia coli, representing a group of Gram-negative species

Cell therapy in surgical treatment of fistulas. Preliminary results

Risk of recurrence after surgical treatment of a recurrent fistula is up to 50%. It has be known that more aggressive surgical treatment is associated with a high risk of anal sphincter damage and leads to incontinence. Several studies have been designed to elaborate minimally invasive treatment of rectovaginal and anal fistulas. The properties of Adipose-derived Stem Cells (ASC) significantly enhance a natural healing potency. Here, we present our experience with combined surgical and cell therapy in the treatment of fistulas. Materials and Methods: Four patients were enrolled in our study after unsuccessful treatments in the past – patients 1-3 with rectovaginal fistulas including two women after graciloplasty, and patient 4 - a male with complex perianal fistula. Adipose tissue was obtained from subcutaneous tissue. ASCs were isolated, cultured up to 10+/-2 mln cells and injected into the walls of fistulas. Follow-up physical examination and anoscopy were performed at 1, 4, 8, and 12 weeks, 6 and 12 months after implantation. Results: Up to 8 weeks after ASC implantation, symptoms of fistulas’ tracts disappeared. At 8 weeks, in patients 1-3, communication between vaginal and rectal openings was closed and at 12-16 w. intestinal continuity was restored in patient 3 and 4. After a 6-month follow-up, the fistula tract of patient 4 was closed. Up to 12 m. after ASC implantation no recurrences or adverse events were observed. Conclusion: ASCs combined with surgical pre-treated fistula tracts were used in four patients. All of them were healed. This encouraging result needs further trials to evaluate the clinical efficiency and the cost-effectiveness ratio

Terapia komórkowa w chirurgicznym zaopatrzeniu przetok : doniesienia wstępne

Wstęp: Ryzyko niepowodzenia po chirurgicznym leczeniu nawrotowych przetok okołoodbytniczych sięga 50%. Wiadomo także, że im bardziej agresywne leczenie chirurgiczne, tym większe zagrożenie uszkodzenia zwieraczy z objawowym nietrzymaniem stolca. Stąd też trwają poszukiwania małoinwazyjnych metod leczenia. Własności mezenchymalnych komórek macierzystych (ASC, Adipose-derived Stem Cells) istotnie wspomagają procesy gojenia tkanek miękkich. W niniejszej pracy przedstawiamy własne wstępne doświadczenia leczenia przetok odbytniczych i odbytniczo-pochwowych z zastosowaniem ASC. Materiały i metody: Do leczenia zakwalifikowano 4 pacjentów po uprzednich, nieskutecznych zabiegach chirurgicznego leczenia przetok: mężczyznę z nawrotową przetoką przezzwieraczową i 3 kobiety z przetokami odbytniczo-pochwowymi, w tym 2 po uprzednim przeszczepie mięśnia smukłego i wyłonieniu stomii. Od pacjentów pobrano 3–10 ml tkanki tłuszczowej, wyizolowano i wyhodowano ASC. 10+/-2 mln komórek w roztworze Ringera implantowano w ściany przetoki. Ocenę gojenia (wywiad, badanie fizykalne i anoskopia) przetok prowadzono w 1., 4., 8. i 12. tygodniu oraz 6. i 12. miesiącu po podaniu ASC. Wyniki: Pomiędzy 4. a 8. tygodniem u wszystkich pacjentów ustąpiły subiektywne objawy przetoki. U pacjentek z wyłonioną stomią ciągłość przewodu pokarmowego odtworzono w 12.–16. tygodniu od podania ASC. U pacjenta z odkryptową przetoką odbytniczą 6 miesięcy po implantacji nie obserwowano cech przetoki. Zagojenie uzyskano u wszystkich pacjentów. Po 12 miesiącach od zastosowania terapii komórkowej nie stwierdzono nawrotu przetoki ani zdarzeń niepożądanych. Wnioski: Implantacja ASC w przygotowaną chirurgicznie ścianę przetoki z powodzeniem została zastosowana u 4 pacjentów. Uzyskano wygojenie u wszystkich chorych. Konieczne są dalsze badania oceniające efektywność i koszty takiego leczenia