A diverse range of normal flora populates the human skin and numbers are relatively different between individuals and parts of the skin. Humans and normal flora have formed a symbiotic relationship over a period of time. With numerous disease processes, the interaction between the host and normal flora can be interrupted. Unlike normal wound healing, which is complex and crucial to sustaining the skin’s physical barrier, chronic wounds, especially in diabetes, are wounds that fail to heal in a timely manner. The conditions become favorable for microbes to colonize and establish infections within the skin. These include secretions of various kinds of molecules, substances or even trigger the immune system to attack other cells required for wound healing. Additionally, the healing process can be slowed down by prolonging the inflammatory phase and delaying the wound repair process, which causes further destruction to the tissue. Antibiotics and wound dressings become the targeted therapy to treat chronic wounds. Though healing rates are improved, prolonged usage of these treatments could become ineffective or microbes may become resistant to the treatments. Considering all these factors, more studies are needed to comprehensively elucidate the role of human skin normal flora at the cellular and molecular level in a chronic injury. This article will review wound healing physiology and discuss the role of normal flora in the skin and chronic wounds.

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Objective:The objective of this study was to evaluate and compare the two scanning electron microscope (SEM) preparation protocols and determine the better SEM preparation technique to study stem cells on human amniotic membrane (hAM) scaffold.Materials and Methods:Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold.Results:The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality.Conclusions:To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.

BackgroundLignosus rhinocerus (L. rhinocerus), which is known locally as Tiger Milk mushroom, is traditionally used in the treatment of asthma by indigenous communities in Malaysia. However, to date, its efficacy on asthma has not been confirmed by scientific studies and there is also sparse information available on its active constituents. In this study, the volatile constituent of L. rhinocerus hot water extract was investigated using gas chromatography mass spectrometry (GC-MS). The potential effects of L. rhinocerus extract for anti-asthmatic activity was further investigated on ovalbumin (OVA)-sensitized asthmatic Sprague Dawley rats.MethodsSequential extraction using five solvents (petroleum ether, diethyl ether, hexane, ethyl acetate and methanol) was conducted prior to GC-MS analysis. Male Sprague Dawley rats were divided into the following four groups of five animals each: 1) normal rats, 2) sensitization plus OVA-challenged rats 3) sensitization plus OVA-challenged with L. rhinocerus treatment and 4) sensitization plus OVA-challenged with dexamethasone treatment. The levels of immunoglobulin E (IgE) in the serum and T-helper 2 cytokines, including interleukin (IL)-4, IL-5 and IL-13, in bronchoalveolar lavage fluid (BALF), as well as eosinophil infiltration in the lungs, were investigated.ResultsGC-MS analysis revealed the presence of five main groups (alkane, fatty acids, benzene, phenol and dicarboxylic acid) with a total of 18 constituents. Linoleic acid (21.35 %), octadecane (11.82 %) and 2,3-dihydroxypropyl elaidate (10.47 %) were present in high amounts. The extract significantly ameliorated the increase in total IgE in serum and IL-4, IL-5 and IL-13 levels in BALF and also effectively suppressed eosinophils numbers in BALF while attenuating eosinophil infiltrations in the lungs.ConclusionL. rhinocerus hot water extract has the potential to be used as an alternative for the treatment of acute asthma.

Stem cells derived from human exfoliated deciduous teeth (SHED) represent a promising cell source for bone tissue regeneration. This study evaluated the effects of interleukin-17A (IL-17A) on the osteogenic differentiation of SHED. SHED were cultured in complete alpha minimum essential medium supplemented with osteoinducing reagents and treated with recombinant IL-17A. The cells were quantitatively analysed for proliferative activity by MTS assay, cell markers expression, and apoptotic activity by flow cytometry. For osteogenic differentiation, alkaline phosphatase (ALP) activity was quantified; mineralization assays were carried out using von Kossa and Alizarin red, and expression of osteogenic markers were analysed by real-time polymerase chain reaction and Western blot. The results showed that treatment with IL-17A increased proliferative activity in a dose-dependent manner, but reduced the expression of stem cell markers (c-Myc and Nanog) as the days progressed. IL-17A induced osteogenic differentiation in SHED as evidenced by high ALP activity, increased matrix mineralization, and upregulation of the mRNA expression of the osteogenic markers ALP, alpha 1 type 1 collagen (Col1A1), runt-related transcription factor 2 (RUNX2), osteopontin (OPN), osteocalcin (OCN), and osteoprotegerin (OPG) but downregulation of receptor activator of nuclear factor κB ligand (RANKL) as well as altering the OPG/RANKL ratio. Findings from our study indicate that IL-17A enhances proliferation and osteogenic differentiation of SHED by regulating OPG/RANKL mechanism thus suggests therapeutic potential of IL-17A in bone regeneration.

Osteoarthritis (OA) is a chronic degenerative disorder of the joint and its prevalence and severity is increasing owing to ageing of the population. Osteoarthritis is characterized by the degradation of articular cartilage and remodeling of the underlying bone. There is little understanding of the cellular and molecular processes involved in pathophysiology of OA. Currently the treatment for OA is limited to painkillers and anti-inflammatory drugs, which only treat the symptoms. Some patients may also undergo surgical procedures to replace the damaged joints. Extracellular vesicles (EV) play an important role in intercellular communications and their concentration is elevated in the joints of OA patients, although their mechanism is unclear. Extracellular vesicles are naturally released by cells and they carry their origin cell information to be delivered to target cells. On the other hand, mesenchymal stem cells (MSCs) are highly proliferative and have a great potential in cartilage regeneration. In this review, we provide an overview of the current OA treatments and their limitations. We also discuss the role of EV in OA pathophysiology. Finally, we highlight the therapeutic potential of MSC-derived EV in OA and their challenges.

Effective pulp capping material must be biocompatible and have the ability to induce dentin bridge formation as well as having suitable physical and mechanical properties; however, many current materials do not satisfy the clinical requirements. This study aimed to assess the physical and mechanical properties of gypsum-based chitosan material (Gp-CT) and to evaluate its effects on cellular properties of stem cells from human exfoliated deciduous teeth (SHED). The experimental material was prepared with different concentrations of chitosan (CT) with or without BMP-2. Then, setting time, compressive strength, and pH were determined. In addition, cell viability, alkaline phosphatase (ALP) activity, and cell attachment were assessed. The setting time, compressive strength, and pH obtained were 4.1–6.6 min, 2.63–5.83 MPa, and 6.5–5.7, respectively. The cell viability to gypsum (Gp) with different CT concentrations was similar to that of the control on day 1 but statistically different from that of Gp alone on day 3. The ALP activity of SHED was significantly higher (p < 0.05) in CT- and BMP-2-containing materials than those in the control and Dycal at days 3 and 14. The scanning electron microscopy (SEM) image revealed that flattened cells were distributed across and adhered to the material surface. In conclusion, Gp-CT material shows promise as a potential material for direct pulp capping.

Asthma is a chronic inflammatory disorder in the airways that involves the activation of cells and mediators. Lignosus rhinocerotis (Cooke) Ryvardan or Tiger Milk mushroom is a medicinal mushroom that is traditionally used to treat inflammatory diseases including asthma. In this study, the protective effects of intranasal administration of L. rhinocerotis extract (LRE) in ovalbumin (OVA)-induced airway inflammation mouse model were investigated. Mice were sensitized by intraperitoneal (i.p) injection on days 0 and 14, followed by a daily challenge with 1% OVA from days 21 to 27. Following OVA challenge, LRE and dexamethasone were administered via intranasal and i.p. injection respectively. On day 28, the level of serum immunoglobulin (Ig)E, differential cell counts and T-helper (Th) 2 cytokines in bronchoalveolar lavage fluid (BALF) fluid, cell subset population in lung-draining lymph nodes (LNs), leukocytes infiltration and mucus production in the lungs of the animals was measured. Results demonstrated that intranasal administration of LRE significantly suppressed the level of inflammatory cell counts in BALF as well as populations of CD4 + T-cells in lung draining LNs. Apart from that, LRE also significantly reduced the level of Th2 cytokines in BALF and IgE in the serum in OVA-induced asthma. Histological analysis also demonstrated the amelioration of leukocytes infiltration and mucus production in the lungs. Overall, these findings demonstrated the attenuation of airway inflammation in the LRE-treated mice therefore suggesting a promising alternative for the management of allergic airway inflammation.