The Combined Effects of Mesenchymal Stem Cell Conditioned Media and Low-Level Laser on Stereological and Biomechanical Parameter in Hypothyroidism Rat Model

Impact of short and long-term application of low-level laser therapy on mandibular alveolar process of osteoporotic rats - a Histological and Molecular Study

This study aims to investigate and compare the effects of short and long-term application of low-level laser therapy on the mandibular alveolar process of osteoporotic rats. Forty adult male albino rats were included in this study. After animal grouping, the experimental group received dexamethasone (0.1 mg/kg b.wt./day for 60 days) for the induction of osteoporosis, then the rats were treated using LLLT (830 nm, 100 mW, at 60 J/cm2). The lower jaw specimens were collected and processed for histological, molecular, and histomorphometric assessments. The osteoporotic group exhibited alveolar bone resorption, accompanied by significantly upregulated RANKL and downregulated OPG mRNA expression. The short-term application of laser group showed alveolar bone partial improvement with slightly downregulated RANKL and slightly upregulated OPG levels. The long-term application of laser group showed dramatic positive changes in the alveolar bone, with markedly downregulated RANKL and upregulated OPG levels. LLLT shows potential as a low-risk and impactful local management for osteoporosis, with long-term laser application demonstrably improving bone quality, quantity, and organization compared to short-term application.

Photobiomodulation and mesenchymal stem cell-conditioned medium for the repair of experimental critical-size defects

Orthopedic surgeons face a significant challenge in treating critical-size femoral defects (CSFD) caused by osteoporosis (OP), trauma, infection, or bone tumor resections. In this study for the first time, the application of photobiomodulation (PBM) and bone marrow mesenchymal stem cell-conditioned medium (BM-MSC-CM) to improve the osteogenic characteristics of mineralized bone scaffold (MBS) in ovariectomy-induced osteoporotic (OVX) rats with a CSFD was tested. Five groups of OVX rats with CSFD were created: (1) Control (C); (2) MBS; (3) MBS + CM; (4) MBS + PBM; (5) MBS + CM + PBM. Computed tomography scans (CT scans), compression indentation tests, and histological and stereological analyses were carried out after euthanasia at 12 weeks following implantation surgery. The CT scan results showed that CSFD in the MBS + CM, MBS + PBM, and MBS + CM + PBM groups was significantly smaller compared to the control group (p = 0.01, p = 0.04, and p = 0.000, respectively). Moreover, the CSFD size was substantially smaller in the MBS + CM + PBM treatment group than in the MBS, MBS + CM, and MBS + PBM treatment groups (p = 0.004, p = 0.04, and p = 0.01, respectively). The MBS + PBM and MBS + CM + PBM treatments had significantly increased maximum force relative to the control group (p = 0.01 and p = 0.03, respectively). Bending stiffness significantly increased in MBS (p = 0.006), MBS + CM, MBS + PBM, and MBS + CM + PBM treatments (all p = 0.004) relative to the control group. All treatment groups had considerably higher new trabecular bone volume (NTBV) than the control group (all, p = 0.004). Combined therapies with MBS + PBM and MBS + CM + PBM substantially increased the NTBV relative to the MBS group (all, p = 0.004). The MBS + CM + PBM treatment had a markedly higher NTBV than the MBS + PBM (p = 0.006) and MBS + CM (p = 0.004) treatments. MBS + CM + PBM, MBS + PBM, and MBS + CM treatments significantly accelerated bone regeneration of CSFD in OVX rats. PBM + CM enhanced the osteogenesis of the MBS compared to other treatment groups.

Low-Level Laser and Bovine Amniotic Fluid-derived Cream Accelerating Skin Neck Wound Healing and Reducing Inflammation and Wound Scar in a Rat Animal Model

Background

Nowadays, wound healing is one of the main problems of patients. Therefore, extensive research is underway to discover mechanisms associated with non-scarring of wounds. Using amniotic fluid and laser may potentially play a key role in wound healing and scar reduction due to its presence in tissue growth and repair agents.

Aim

The present study evaluated the effect of bovine amniotic fluid (BAF)-derived cream and low-power laser (LPL) on accelerating skin wound healing and reducing scarring in an animal model.

Materials and Methods

Therefore, 72 male Wistar rats were randomly divided into three groups (each group: 24). A wound 6 mm in diameter was then inflicted on the rats' backs. In the first group that was the control group, the wound was only used. Moreover, BAF was implemented for the second group, and in the third group, LPL radiation was utilized. On the 1st, 3rd, 5th, 14th, and 21st days, the healing condition of the wound and scar created were examined.

Results

Hence, evaluation of wound healing status on days 5 and 14 showed that the wound healing scale in the BAF group and LPL group was significantly better than that of the control group. On the 21st day, the average Scar Scoring Scale in the BAF and LPL groups was significantly lower than that of the control group. Histological images showed a significant repair in the LPL and BAF groups.

Conclusion

To conclude, considering the positive effect of LPL and BAF on wound healing and less scarring, it seems that LPL and BAF can heal wounds faster. Moreover, they can be used to prevent scarring after wound healing.

Steering the multipotent mesenchymal cells towards an anti-inflammatory and osteogenic bias via photobiomodulation therapy: How to kill two birds with one stone

The bone marrow-derived multipotent mesenchymal cells (MSCs) have captured scientific interest due to their multi-purpose features and clinical applications. The operational dimension of MSCs is not limited to the bone marrow reservoir, which exerts bone-building and niche anabolic tasks; they also meet the needs of quenching inflammation and restoring inflamed tissues. Thus, the range of MSC activities extends to conditions such as neurodegenerative diseases, immune disorders and various forms of osteopenia. Steering these cells towards becoming an effective therapeutic tool has become mandatory. Many laboratories have employed distinct strategies to improve the plasticity and secretome of MSCs. We aimed to present how photobiomodulation therapy (PBM-t) can manipulate MSCs to render them an extraordinary anti-inflammatory and osteogenic instrument. Moreover, we discuss the outcomes of different PBM-t protocols on MSCs, concluding with some perplexities and complexities of PBM-t in vivo but encouraging and feasible in vitro solutions.

Photobiomodulation enhances facial nerve regeneration via activation of PI3K/Akt signaling pathway-mediated antioxidant response

Facial nerve dysfunction is a common clinical condition that leads to disfigurement and emotional distress in the affected individuals. This study aimed to evaluate whether photobiomodulation can enhance regeneration of crushed facial nerves and attempt to investigate the possible underlying mechanism of neuroprotective function and therapeutic target. Various parameters of photobiomodulation were assigned to the facial nerves and Schwann cells (SCs) separately during crushed injury in rats. Axonal regeneration, functional outcomes, and SC apoptosis, proliferation, and underlying mechanisms of action were evaluated by morphological, histopathological, and functional assessments, flow cytometry, western blotting, real-time PCR, and IncuCyte. The results showed that photobiomodulation improved axonal regeneration and functional recovery, and also promoted proliferation, and inhibited apoptosis of SCs, both of these were considered as the most effective parameters in 250mW group. In addition, the neuroprotective effects of photobiomodulation (500mW) were likely associated with oxidative stress-induced SC apoptosis via activation of the PI3K/Akt signaling pathway. Our results revealed that photobiomodulation significantly promoted axonal regeneration, functional recovery, and regeneration of the facial nucleus, and its mechanism was related to the up-regulation of the PI3K/Akt signaling pathway. These findings provide clear experimental evidence of photobiomodulation as an alternative therapeutic strategy for peripheral nerve damage.

The Effect of Low-Level Laser Therapy and Curcumin on the Expression of LC3, ATG10 and BAX/BCL2 Ratio in PC12 Cells Induced by 6-Hydroxide Dopamine

Introduction: Parkinson's disease (PD) is one of the most common neurodegenerative disorders. The neuroinflammation in the brain of PD patients is one of the critical processes in the immune pathogenesis of PD leading to the neural loss in the substantia nigra. Due to the anti-inflammatory effects of curcumin (CU) and low-level laser therapy (LLLT), we examined the protective effect of CU and LLLT on PC12 cells treated with 6-hydroxydopamine (6-OHDA) as a Parkinson model. Methods: PC12 cells were pretreated using various concentrations of 6-OHDA for 24 hours to induce oxidative and cellular damages. PC12-6-OHDA cells were co-treated with CU and LLLT. The effects of CU and LLLT on Bax/Bcl2 and LC3/ATG10 expression were analyzed by real-time PCR and cell viability was assessed by MTT assay. Cell A Software was used to calculate the length of the Neurite and cell body areas. Results: The results of this study show that the combination of CU dose-dependently and LLLT has a significant neuroprotective effect on cells and cellular death significantly decreases by increasing CU concentration. CU+LLLT decreases Bax/Bcl2 ratio which is an indicator of apoptosis and it also rescued a decrease in LC3 and ATG10 expression in comparison with 6-OHDA group. Conclusion: This study shows that the combination of 5 μM CU and LLLT has the best neuroprotective effect on PC12 cells against 6-OHDA by decreasing the BAX/BCL2 ratio.

The Effect of Photobiomodulation Therapy on the Differentiation, Proliferation, and Migration of the Mesenchymal Stem Cell: A Review

Introduction: The purpose of this study is to investigate the effect of a low-power laser on the proliferation, migration, differentiation of different types of mesenchymal stem cells (MSCs) in different studies. Methods: The relevant articles that were published from 2004 to 2019 were collected from the sources of PubMed, Scopus, and only the articles specifically examining the effect of a lowpower laser on the proliferation, differentiation, and migration of the MSCs were investigated. Results: After reviewing the literature, only 42 articles were found relevant. Generally, most of the studies demonstrated that different laser parameters increased the proliferation, migration, and differentiation of the MSCs, except the results of two studies which were contradictory. In fact, changing the parameters of a low-power laser would affect the results. On the other hand, the source of the stem cells was reported as a key factor. In addition, the combination of lasers with other therapeutic approaches was found to be more effective. Conclusion: The different parameters of lasers has been found to be effective in the proliferation, differentiation, and migration of the MSCs and in general, a low-power laser has a positive effect on the MSCs, helping to improve different disease models.