The inflammatory stimulus of a natural latex biomembrane improves healing in mice

The aim of the present study was to compare healing obtained with biomembranes with the natural healing process (sham) using biochemical and immunohistological assays. C57BL/6 mice were divided into 4 groups of 15 mice each and received different subcutaneous implants: natural latex biomembrane (NLB), denatured latex (DL), expanded polytetrafluorethylene (ePTFE), or sham. On the 2nd, 7th, and 14th days post-treatment, 5 mice per group were sacrificed and biopsied for the following measurements: oxidative stress based on malondialdehyde (MDA), myeloperoxidase (MPO) and hydrogen peroxide by the method of ferrous oxidation-xylenol orange (FOX), as well as glutathione and total proteins; histological evaluation to enumerate inflammatory cells, fibroblasts, blood vessels, and collagen, and immunohistochemical staining for inducible nitric oxide synthase, interleukin-1&#946;, vascular endothelial growth factor (VEGF), and transforming growth factor-&#946;1 (TGF-&#946;1). On day 2 post-treatment, NLB stimulated a dense inflammatory infiltrate mainly consisting of polymorphonuclear cells, as indicated by increased MPO (P < 0.05), but oxidative stress due to MDA was not observed until the 7th day (P < 0.05). The number of blood vessels was greater in NLB (P < 0.05) and DL (P < 0.05) mice compared to sham animals on day 14. NLB induced fibroplasia by day 14 (P < 0.05) with low expression of TGF-&#946;1 and collagenesis. Thus, NLB significantly induced the inflammatory phase of healing mediated by oxidative stress, which appeared to influence the subsequent phases such as angiogenesis (with low expression of VEGF) and fibroplasia (independent of TGF-&#946;1) without influencing collagenesis

Antimicrobial activity of copaíba (Copaifera langsdorffii) oleoresin on bacteria of clinical significance in cutaneous wounds

The present study was designed to evaluate the in vitro antimicrobial activity of Copaifera langsdorffii oleoresin, which has been used in folk medicine as an anti-inflammatory, antibacterial, healing among others. The oleoresin was tested against Gram-positive (Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria related to infections in cutaneous wounds. Antimicrobial activity was determined by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Copaiba oleoresin showed antimicrobial activity only against the Gram-positive bacteria with MIC of 200 &#956;g/mL, 400 &#956;g/mL and 1100 &#956;g/mL for S. aureus, S. pyogenes and E. faecalis, respectively. MBC values were the same as MIC for S. aureus and S. pyogenes and for E. faecalis it was 1200 &#956;g/mL. Considering that infection significantly impairs the wound healing process, we believe that the use of copaiba oleoresin as a component of a topical formulation could be a valuable adjunct in the treatment of infected wounds, mainly in the case of wounds infected by Gram-positive microorganisms

Tissue Constructs with Human Adipose-Derived Mesenchymal Stem Cells to Treat Bone Defects in Rats

The use of porous scaffolds created by additive manufacturing is considered a viable approach for the regeneration of critical-size bone defects. This paper investigates the xenotransplantation of polycaprolactone (PCL) tissue constructs seeded with differentiated and undifferentiated human adipose-derived mesenchymal stem cells (hADSCs) to treat calvarial critical-sized defect in Wistar rats. PCL scaffolds without cells were also considered. In vitro and in vivo biological evaluations were performed to assess the feasibility of these different approaches. In the case of cell seeded scaffolds, it was possible to observe the presence of hADSCs in the rat tissue contributing directly (osteoblasts) and indirectly (stimulation by paracrine factors) to tissue formation, organization and mineralization. The presence of bone morphogenetic protein-2 (BMP-2) in the rat tissue treated with cell-seeded PCL scaffolds suggests that the paracrine factors of undifferentiated hADSC cells could stimulate BMP-2 production by surrounding cells, leading to osteogenesis. Moreover, BMP-2 acts synergistically with growth factors to induce angiogenesis, leading to higher numbers of blood vessels in the groups containing undifferentiated and differentiated hADSCs