Lactobacillus johnsonii LJO02 (DSM 33828) Cell-Free Supernatant and Vitamin D Improve Wound Healing and Reduce Interleukin-6 Production in Staphylococcus aureus-Infected Human Keratinocytes

Methicillin-resistant biofilm-forming Staphylococcus spp. are found in about 25% of the overall cases of chronic wounds, which can undergo malignant degeneration and be associated with skin cancer. Although antimicrobial agents are clinically used to counteract pathogens and promote wound healing, they are increasingly ineffective against multi-drug resistant bacteria. Moreover, they can induce dysbiosis, which favors opportunistic pathogen infections and alters immune responses. Consequently, research on pathogen containment strategies is crucial. We aimed to evaluate the potential beneficial effect of Lactobacillus johnsonii LJO02 cell-free supernatant (CFS) and vitamin D, as single treatments or in combination, on cell viability, wound healing, and the pro-inflammatory interleukin-6 (IL-6) production of a Staphylococcus aureus-infected human immortalized keratinocyte cell line (HaCaT) in vitro model. The analysis showed that LJO02 CFS 20% v/v ratio and 100 nM vitamin D promoted infected cell viability and wound healing and significantly reduced IL-6 production. However, their effect was not synergic, since no significant difference between the single and combined treatments was observed. LJO02 CFS topic application and vitamin D supplementation could provide a valuable strategy for attenuating S. aureus-induced pathogenesis, promoting wound healing and opening new therapeutic strategies supporting the conventional approaches

Non-Melanoma Skin Cancer: news from microbiota research

Recently, research has been deeply focusing on the role of the microbiota in numerous diseases, either affecting the skin or other organs. What it is well established is that its dysregulation promotes several cutaneous disorders (i.e. psoriasis and atopic dermatitis). To date, little is known about its composition, mediators and role in the genesis, progression and response to therapy of Non-Melanoma Skin Cancer (NMSC). Starting from a bibliographic study, we classified the selected articles into four sections: i) normal skin microbiota; ii) in vitro study models; iii) microbiota and NMSC and iv) probiotics, antibiotics and NMSC. What has emerged is how skin microflora changes, mainly represented by increases of Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa strains, modifications in the mutual quantity of \u3b2-Human papillomavirus genotypes, of Epstein Barr Virus and Malassezia or candidiasis, may contribute to the induction of a state of chronic self-maintaining inflammation, leading to cancer. In this context, the role of S. aureus and that of specific antimicrobial peptides look to be prominent. Moreover, although antibiotics may contribute to carcinogenesis, due to their ability to influence the microbiota balance, specific probiotics, such as Lacticaseibacillus rhamnosus GG, Lactobacillus johnsonii NCC 533 and Bifidobacteria spp., may be protective

Bioreactor mechanically guided 3D mesenchymal stem cell chondrogenesis using a biocompatible novel thermo-reversible methylcellulose-based hydrogel

Autologous chondrocyte implantation for cartilage repair represents a challenge because strongly limited by chondrocytes' poor expansion capacity in vitro. Mesenchymal stem cells (MSCs) can differentiate into chondrocytes, while mechanical loading has been proposed as alternative strategy to induce chondrogenesis excluding the use of exogenous factors. Moreover, MSC supporting material selection is fundamental to allow for an active interaction with cells. Here, we tested a novel thermo-reversible hydrogel composed of 8% w/v methylcellulose (MC) in a 0.05 M Na 2 SO 4 solution. MC hydrogel was obtained by dispersion technique and its thermo-reversibility, mechanical properties, degradation and swelling were investigated, demonstrating a solution-gelation transition between 34 and 37 °C and a low bulk degradation (<20%) after 1 month. The lack of any hydrogel-derived immunoreaction was demonstrated in vivo by mice subcutaneous implantation. To induce in vitro chondrogenesis, MSCs were seeded into MC solution retained within a porous polyurethane (PU) matrix. PU-MC composites were subjected to a combination of compression and shear forces for 21 days in a custom made bioreactor. Mechanical stimulation led to a significant increase in chondrogenic gene expression, while histological analysis detected sulphated glycosaminoglycans and collagen II only in loaded specimens, confirming MC hydrogel suitability to support load induced MSCs chondrogenesis

Bioreactor mechanically guided 3D mesenchymal stem cell chondrogenesis using a biocompatible novel thermo-reversible methylcellulose-based hydrogel

Autologous chondrocyte implantation for cartilage repair represents a challenge because strongly limited by chondrocytes' poor expansion capacity in vitro. Mesenchymal stem cells (MSCs) can differentiate into chondrocytes, while mechanical loading has been proposed as alternative strategy to induce chondrogenesis excluding the use of exogenous factors. Moreover, MSC supporting material selection is fundamental to allow for an active interaction with cells. Here, we tested a novel thermo-reversible hydrogel composed of 8% w/v methylcellulose (MC) in a 0.05 M Na 2 SO 4 solution. MC hydrogel was obtained by dispersion technique and its thermo-reversibility, mechanical properties, degradation and swelling were investigated, demonstrating a solution-gelation transition between 34 and 37 °C and a low bulk degradation (<20%) after 1 month. The lack of any hydrogel-derived immunoreaction was demonstrated in vivo by mice subcutaneous implantation. To induce in vitro chondrogenesis, MSCs were seeded into MC solution retained within a porous polyurethane (PU) matrix. PU-MC composites were subjected to a combination of compression and shear forces for 21 days in a custom made bioreactor. Mechanical stimulation led to a significant increase in chondrogenic gene expression, while histological analysis detected sulphated glycosaminoglycans and collagen II only in loaded specimens, confirming MC hydrogel suitability to support load induced MSCs chondrogenesis

Data on Manuka Honey/Gellan Gum composite hydrogels for cartilage repair

This work contains original data supporting our research paper “Antibacterial effectiveness meets improved mechanical properties: Manuka Honey/Gellan Gum composite hydrogels for cartilage repair”, Bonifacio et al., in press [1], in which innovative composite hydrogels, based on Gellan Gum/Manuka honey/Halloysite nanotubes were described as biomaterials for cartilage regeneration. Here the composites were further examined by means of Fourier Transform Infrared Spectroscopy, in Attenuated Total Reflectance mode (FT-IR/ATR). Materials devoted to cartilage replacement must possess adequate fluid permeability and lubricating capability, therefore, a deeper investigation on water uptake kinetics of freeze-dried specimens up to 21 days in PBS was carried out. Moreover, since the degradation rate of a biomaterial plays a pivotal role in tissue engineering, weight loss measurements of the prepared hydrogels were performed in simulated synovial fluid, in phosphate buffer solution (PBS) and in lysozyme. Scanning Electron Microscopy images provide insight into the morphology of the freeze-dried samples. Finally, additional information on Staphylococcus aureus and Staphylococcus epidermidis ability to adhere onto the prepared hydrogel composites in short times were obtained, as well as the chondrogenic potential of the composites assessed by SDS-PAGE followed by Coomassie blue gel staining

Cytotoxic activity of a plant extract on cancer cells

Chemoprevention by natural products may be considered a promising approach to cancer control and management [1]. Many studies have demonstrated antiproliferative, cytostatic and cytotoxic activities of phytochemicals against cancer cells [2]. In this study, a plant extract from Arctium lappa, Berberis vulgaris and Eschscholtia californica was tested as potential anticancer agent. The antitumoral activity of this plant extract was tested on four human cancer cell lines: MCF-7 (breast carcinoma cells), Huh-7 (hepatic carcinoma cells), HTB-43 (oropharyngeal carcinoma cells) and ECV- 304 (urinary bladder carcinoma cells). The efficacy of the extract was compared to the common chemotherapeutic agent cyclophosphamide. Three plant extract concentrations were tested: 800, 650 and 450 ng/ml; for cyclophosphamide, three concentrations were assayed, according to literature data: 1300, 1000 and 850 ng/ml [3]. In addition, plant extract and cyclophosphamide were tested on two primary cell lines as controls, human gingival fibroblasts and human mammary fibroblasts. Cell viability was evaluated by the MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Sigma] colorimetric assay and the new xCELLigence system (Roche) for real-time monitoring of cell viability. All concentrations of plant extract exhibited a high level of cytotoxicity on MCF-7, Huh-7, HTB-43 and ECV-304 cancer cells, similar to cyclophosphamide, though they slightly reduced viability of human gingival and mammary fibroblasts. Conversely, the conventional chemotherapeutic drug showed a marked cytotoxicity on control cells. The potential of the plant extract has been demonstrated in vitro on various types of cancers, suggesting a possible use of this natural product as a promising anticancer agent. Further studies are needed to ascertain its efficacy in vivo and to elucidate its mechanism(s) of action at molecular and biochemical levels