Eduardo Mainieri Chem

Isolation of adipose-derived stem cells: a comparison among different methods.

Adipose-derived stromal cells (ASCs) are usually isolated by digestion with collagenase. We have compared alternative methods to isolate ASCs in a more economically viable protocol. Nine protocols using red blood cells lysis buffer solution, trypsin, collagenase and centrifugation were compared; the isolation rate, cell viability, expansion rate, immunophenotype and differentiation in adipogenic and osteogenic lineages were analyzed. ASCs were isolated and successfully maintained by digestion with trypsin. Cells presented similar immunophenotypes, adipogenic differentiation and in vitro proliferation but an osteogenic differentiation capacity up to seven times higher than ASCs isolated by collagenase. This alternative protocol is thus efficient and more cost-effective than the commonly-used methods and may represent a promising protocol for obtaining ASCs for bone tissue engineering.

Human mesenchymal stem cells are resistant to cytotoxic and genotoxic effects of cisplatin in vitro

Abstract Mesenchymal stem cells (MSCs) are known for their important properties involving multilineage differentiation potential., trophic factor secretion and localization along various organs and tissues. On the dark side, MSCs play a distinguished role in tumor microenvironments by differentiating into tumor-associated fibroblasts or supporting tumor growth via distinct mechanisms. Cisplatin (CIS) is a drug widely applied in the treatment of a large number of cancers and is known for its cytotoxic and genotoxic effects, both in vitro and in vivo. Here we assessed the effects of CIS on MSCs and the ovarian cancer cell line OVCAR-3, by MTT and comet assays. Our results demonstrated the resistance of MSCs to cell death and DNA damage induction by CIS, which was not observed when OVCAR-3 cells were exposed to this drug.

Interaction of Human, Canine and Murine Adipose-Derived Stem Cells with Different Biomaterials

Due to ease of collection and in vitro expansion, abundance and plasticity, adipose-derived stem cells (ADSC) represent an attractive option for cell therapy and tissue engineering. A variety of biodegradable scaffolds are used as substitutes for the artificial extracellular matrix. Among them are biomaterials consisting of biomolecules such as collagen and poly (L-lactic acid) (OPLA), and bioceramics such as calcium phosphate. As an advantage compared to conventional twodimensional (2D) cell culture, scaffolds provide an adhesive substrate that also serves as a physical support matrix for cell culture in vitro. The present work aimed to investigate the patterns of adherence and proliferation of human, canine and murine ADSC on these three types of biomaterials. Adipose tissue was obtained from patients undergoing elective liposuction, adult C57BL/6 mice and canine healthy donors. ADSC were isolated with use of collagenase, cultured and characterized. Cells between passages 4 and 7 were associated with 3D scaffolds of calcium phosphate, collagen and OPLA (BD Biosciences), dry or pre-coated with medium with 10% fetal calf serum. Different cell concentrations were used: 104 and 5x104 cells/scaffold. Cell adherence was evaluated by counting nonadhered cells stained with Giemsa. The proliferation of ADSC in 2D and 3D conditions after 3-day incubation was determined using the MTT test. The cells adhered best to dry scaffolds, and the concentration of 5x104 cells/scaffold was the most adequate for adherence and proliferation. Human ADSC proliferated more rapidly on 2D than in 3D conditions, contrary to murine and canine cells. These results show that cultivation of ADSC from different species in degradable biomaterials is feasible and may be exploited for the therapeutic use of these compounds.

Human Skin Bank

The skin bank has as its main functions the harvesting, processing, preservation, and supply of fine human skin allografts for burn treatment centers and polytrauma. Skin donation can be made from individuals who have died with the diagnosis of brain death or cardiac arrest. The skin harvesting involves removing thin slices of skin from the donor. The processing of the skin begins while the donor is still in the operating room. Skin processing continues in the skin bank and can be divided into three distinct phases. After each stage of processing, skin fragments are collected for microbiological analysis. The skin bank follows international guidelines, whereby the tissue acceptability criteria take into account the degree of pathogenicity of the organism and its potential to produce toxins. Storage of the skin can be accomplished in two distinct ways, each with a direct relationship to the type of processing performed: glycerol under refrigeration or cryopreservation. The release and distribution of allogeneic skin for clinical use only occurs after certification of tissue sterility. The tissue is distributed to all burn treatment units of the country, being governed by the National and Regional Center of transplants. The main clinical indications for the use of allogeneic skin are deep and extensive burns and large skin defects caused by trauma. One of the most critical factors in handling and repairing lesions in patients with major skin loss is adequate coverage of the damaged area to prevent further blood loss and opportunistic bacterial infections.

Allogeneic skin donors from a tissue bank in Southern Brazil: clinical and epidemiological profiles and microbial colonization of skin

An allogeneic human skin graft is a temporary biologic dressing used in extensive burns that can be a providential treatment for affected patients. Skin quality depends directly on its microbial decontamination after processing in a tissue bank. Our objective was to describe the skin donor profiles in relation to the analysis of the microbial colonization of the donated skin.

Prognosis of frontal region video surgery with a modified fixation technique

Introduction: Video endoscopy has become a procedure of choice for the treatment of eyebrow ptosis and forehead wrinkles. This minimally invasive technique has several advantages over traditional coronal incision. Several fixation methods are reported in the literature, with similar results. In this study, we describe direct needle fixation. Objective: To evaluate the prognosis of video endoscopic surgery using a direct needle technique. Method: Computerized photographic evaluations of 37 patients undergoing video endoscopy of the frontal region with needle direct fixation were conducted in two private hospitals in the city of Porto Alegre in Rio Grande do Sul, Brazil. Results: The mean eyebrow elevations were 5.7 and 4.4 mm in the lateral and middle third measurements. After a small dip in elevation in the first month after surgery, the repositioning of the eyebrow remained unchanged in subsequent measurements up to 24 months later. Conclusion: Direct needle fixation produced lasting, reliable, and reproducible results during the period in which measurements were made.