Investigation into antibacterial and wound healing properties of platelets lysate against Acinetobacter baumannii and Klebsiella pneumoniae burn wound infections.

BACKGROUND AND AIM: Treatment of burn wound infections has become a global challenge due to the spread of multidrug-resistant bacteria; therefore, the development of new treatment options for the mentioned infections is essential. Platelets have drawn much attention for this purpose because they are a safe and cost-effective source of different antimicrobial peptides and growth factors. The present study evaluated antibacterial effects and wound healing properties of Platelet-derived Biomaterial (PdB) against Acinetobacter baumannii and Klebsiella pneumoniae burn wound infections. METHODS: PdB was prepared through the freezing and thawing process and then, in vitro antibacterial effect was determined by disk diffusion and broth microdilution methods. Afterward, burn wound was inflicted on 56 rats, infected with both bacteria, and topical administration was performed to evaluate antibacterial effects and wound healing properties of PdB. RESULTS: In vitro results showed that PdB inhibited the growth of A. baumannii in the highest dose (0.5), while we did not detect any inhibitory effects against K. pneumoniae. By contrast, PdB significantly inhibited the growth of bacteria in treated animal wounds compared to the control groups (P value < 0.05). Macroscopic assessments pointed to the significant enhancement of wound closure in the treated animals. In addition, histopathological examination demonstrated that treatment of rats with PdB led to a considerable increase in re-epithelialization and attenuated the formation of granulation tissue (P value < 0.05). CONCLUSION: The use of topical PdB is an attractive strategy for treating A. baumannii and K. pneumoniae burn wound infections because it inhibits bacterial growth and promotes wound healing properties.

Mesenchymal Stem Cells Extract (MSCsE)-Based Therapy Alleviates Xerostomia and Keratoconjunctivitis Sicca in Sjogren's Syndrome-Like Disease.

Sjogren's syndrome (SS) is an autoimmune disease that manifests primarily in salivary and lacrimal glands leading to dry mouth and eyes. Unfortunately, there is no cure for SS due to its complex etiopathogenesis. Mesenchymal stem cells (MSCs) were successfully tested for SS, but some risks and limitations remained for their clinical use. This study combined cell- and biologic-based therapies by utilizing the MSCs extract (MSCsE) to treat SS-like disease in NOD mice. We found that MSCsE and MSCs therapies were successful and comparable in preserving salivary and lacrimal glands function in NOD mice when compared to control group. Cells positive for AQP5, AQP4, α-SMA, CK5, and c-Kit were preserved. Gene expression of AQP5, EGF, FGF2, BMP7, LYZ1 and IL-10 were upregulated, and downregulated for TNF-α, TGF-ß1, MMP2, CASP3, and IL-1ß. The proliferation rate of the glands and serum levels of EGF were also higher. Cornea integrity and epithelial thickness were maintained due to tear flow rate preservation. Peripheral tolerance was re-established, as indicated by lower lymphocytic infiltration and anti-SS-A antibodies, less BAFF secretion, higher serum IL-10 levels and FoxP3+ Treg cells, and selective inhibition of B220+ B cells. These promising results opened new venues for a safer and more convenient combined biologic- and cell-based therapy.

Clinical and Immunological Benefits of OM-85 Bacterial Lysate in Patients with Allergic Rhinitis, Asthma, and COPD and Recurrent Respiratory Infections.

PURPOSE: The aim of this study was to evaluate the efficacy of OM-85 in reducing the incidence of respiratory tract infections (RTIs) in patients with allergic rhinitis, asthma, or chronic obstructive pulmonary disease (COPD), and its effect on immunological parameters, namely serum and secretory IgA levels. METHODS: This was an open-label, prospective, sequential study which included 84 consecutive patients aged 16-65 years, who presented with recurrent (three or more) respiratory infections during the year prior to study entry. In the first year of the study, patients received standard optimized care (SOC), according to their underlying disease condition (asthma, allergic rhinitis, or COPD). In the following year, patients received treatment with OM-85 oral bacterial lysate (one 7 mg capsule daily for ten consecutive days per month, for 3 months), with a 6-month follow-up. Medical history, clinical symptoms, serum, and secretory IgA levels, and the number of infections and exacerbations were evaluated before and after treatment. RESULTS: There was a decrease in the total number of RTIs before the OM-85 treatment period (SOC only) compared to the year before the study start [69/266 (corresponding to a 74 % reduction)] and an additional decrease [38/69 (corresponding to a 45 % reduction)] after OM-85 treatment; p < 0.05. There was also a significant reduction in the total number of exacerbations related to the patients' underlying medical conditions, which decreased from 55 to 35 during OM-85 (+SOC) treatment, corresponding to a reduction of 36 %. In addition, an increase in serum and secretory IgA levels which coincided with the administration of OM-85 was observed. CONCLUSIONS: Our results showed the clinical benefits of OM-85 in reducing RTIs and exacerbations of the underlying medical condition, in patients with allergic rhinitis, asthma, or COPD.

In vitro anti-inflammatory and antibiofilm activities of bacterial lysates from lactobacilli against oral pathogenic bacteria.

Postbiotics are functional biological compounds, such as bacterial lysates (BLs) released from probiotic bacteria. Although postbiotics exert various bioactivities, the anti-inflammatory and antibiofilm activities of BLs against oral pathogenic bacteria have not been investigated. In the present study, pretreatment with BLs extracted from Lactobacillus plantarum and L. rhamnosus GG suppressed the mRNA and protein expression levels of inflammatory mediators induced by the lipopolysaccharide (LPS) of Porphyromonas gingivalis in RAW 264.7 cells. Both BLs attenuated P. gingivalis LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) and activation of nuclear factor-κB (NF-κB), suggesting that BLs inhibit periodontal inflammatory responses by regulating the MAPK and NF-κB signaling pathways. Moreover, both BLs interfered with biofilm formation by Streptococcus mutans; however, they did not eradicate the established S. mutans biofilm. Furthermore, both BLs downregulated gtfB, gtfC, and gtfD responsible for biofilm formation by S. mutans, suggesting that BLs reduce the synthesis of extracellular polysaccharide and thereby reduce S. mutans biofilm. Taken together, these results suggest that BLs of L. plantarum and L. rhamnosus GG can attenuate periodontal inflammation and dental caries and thus contribute to the improvement of oral health.

Intraoperative Stromal Vascular Fraction Therapy Improves Histomorphometric and Vascular Outcomes in Irradiated Mandibular Fracture Repair.

BACKGROUND: Cell-based treatments have demonstrated the capacity to enhance reconstructive outcomes in recent decades but are hindered in clinical utility by regulatory hurdles surrounding cell culture. This investigation examines the ability of a noncultured stromal vascular fraction derived from lipoaspirate to enhance bone healing during fracture repair to further the development of translatable cell therapies that may improve outcomes in irradiated reconstruction. METHODS: Isogenic male Lewis rats were divided into three groups: fracture, irradiated fracture, and irradiated fracture with stromal vascular fraction treatment. Irradiated groups received a fractioned dose of 35 Gy before mandibular osteotomy. Stromal vascular fraction was harvested from the inguinal fat of isogenic donors, centrifuged, and placed intraoperatively into the osteotomy site. All mandibles were evaluated for bony union and vascularity using micro-computed tomography before histologic analysis. RESULTS: Union rates were significantly improved in the irradiated fracture with stromal vascular fraction treatment group (82 percent) compared to the irradiated fracture group (25 percent) and were not statistically different from the fracture group (100 percent). Stromal vascular fraction therapy significantly improved all metrics of bone vascularization compared to the irradiated fracture group and was not statistically different from fracture. Osteocyte proliferation and mature bone formation were significantly reduced in the irradiated fracture group. Bone cellularity and maturity were restored to nonirradiated levels in the irradiated fracture with stromal vascular fraction treatment group despite preoperative irradiation. CONCLUSIONS: Vascular and cellular depletion represent principal obstacles in the reconstruction of irradiated bone. This study demonstrates the efficacy of stromal vascular fraction therapy in remediating these damaging effects and provides a promising foundation for future studies aimed at developing noncultured, cell-based therapies for clinical implementation.

Wound healing properties and antimicrobial activity of platelet-derived biomaterials.

We analyzed the potential antibacterial effects of two different PdB against methicillin-resistant S. aureus and P. aeruginosa. The third-degree burn wound healing effects of PdB was also studied. Blood samples were obtained from 10 healthy volunteers and biological assays of the PdB were performed and the antimicrobial activity against MRSA and P. aeruginosa was determined using disk diffusion (DD), broth microdilution (BMD), and time-kill assay methods. 48 Wistar albino rats were burned and infected with MRSA. Two groups were injected PdB, the control groups were treated with plasma and received no treatment respectively. In the next step, the rats were euthanized and skin biopsies were collected and histopathologic changes were examined. The results of DD and BMD showed that both PdB performed very well on MRSA, whereas P. aeruginosa was only inhibited by F-PdB and was less susceptible than MRSA to PdBs. The time-kill assay also showed that F-PdB has an antibacterial effect at 4 hours for two strains. Histopathological studies showed that the treated groups had less inflammatory cells and necrotic tissues. Our data suggest that PdB may possess a clinical utility as a novel topical antimicrobial and wound healing agent for infected burn wounds.

Elastic plasma protein film blended with platelet releasate accelerates healing of diabetic mouse skin wounds.

BACKGROUND AND OBJECTIVES: The growth factors derived from platelets and plasma proteins mediate the wound-healing process that is characterized by the sequential migration and differentiation of several cell populations that give rise to angiogenesis, collagen synthesis, wound contraction, and re-epithelialization. To evaluate the efficacy of the blood-derived factors in wound healing, we examined a novel wound dressing consisting of concentrated human plasma proteins and platelet releasate (CPPP). MATERIALS AND METHODS: To generate CPPP, plasma proteins and platelets in the peripheral blood (n = 5) were concentrated with the cold ethanol precipitation method. The thrombin obtained from the same blood unit and calcium chloride (CaCl(2)) were mixed to a concentrate. The CPPP has enough strength to dress cutaneous wounds and contains large amounts of cytokines and fibronectin. We applied the CPPP to excisional skin wounds in genetically healing-impaired model mice (n= 5) and the wounds were evaluated 10 days after the operation. RESULTS: The area of CPPP-treated wounds decreased significantly compared with that of the control wounds (65% vs. 94% of the original size, respectively, P= 0.032). The immunostained section revealed a striking effect of CPPP on vascularization compared with the control wounds (13.2 vs. 2.7 vessels per mm(2) as mean vascular density observed in the sections, respectively, P= 0.013). CONCLUSIONS: Our results suggest that CPPP is a promising biologically active dressing for full-thickness skin wounds. CPPP can be an entirely autologous biological dressing, suggesting that it is free from the risk of transmission of pathogens through blood products.