Transplantation of photobiomodulation-preconditioned diabetic stem cells accelerates ischemic wound healing in diabetic rats

Photobiomodulation associated with alginate-based engineered tissue on promoting chondrocytes-derived biological responses for cartilage regeneration

Articular cartilage is a connective tissue with limited self-healing potential, frequently affected by trauma and degenerative changes, leading to osteoarthritis. Photobiomodulation paired with engineered tissue can improve cartilage's poor intrinsic healing and overcome its restricted self-regeneration. In this study, alginate-based scaffolds were fabricated with varying concentrations of CaCl₂ to achieve optimal mechanical, biocompatible, and biodegradable properties. The fluence-dependence of near-infrared (NIR) laser irradiation (830 nm) on chondrocyte viability and proliferation was investigated in a 2D environment across fluences (2.5-10 J/cm2). Optimal conditions of 3 % w/v CaCl₂ and 5 J/cm2 were identified to construct alginate scaffolds and promote chondrocyte growth in 2D and 3D cultures. Single PBM (830 nm, 5 J/cm2) further exhibited a significant relative intensity of collagen type II immunostaining and stimulation of Col2a1 expression in 2D culture. Multiple PBM sessions (830 nm, 5 J/cm2) significantly enhanced chondrocyte proliferation and glycosaminoglycan production in alginate scaffolds, with a protocol of one session every four days being the most effective. Scanning electron microscopy revealed PBM-induced secretory granule formation, corresponding to a significant increase in extracellular vesicle release. Consequently, integrating PBM and alginate-based scaffolds is a promising technique for accelerating and optimizing cartilage regeneration, with potential application in tissue engineering.

The Role of Microvascular Variations in the Process of Intervertebral Disk Degeneration and Its Regulatory Mechanisms: A Literature Review

Microvascular changes are considered key factors in the process of intervertebral disk degeneration (IDD). Microvascular invasion and growth into the nucleus pulposus (NP) and cartilaginous endplates are unfavorable factors that trigger IDD. In contrast, the rich distribution of microvessels in the bony endplates and outer layers of the annulus fibrosus is an important safeguard for the nutrient supply and metabolism of the intervertebral disk (IVD). In particular, the adequate supply of microvessels in the bony endplates is the main source of the nutritional supply for the entire IVD. Microvessels can affect the progression of IDD through a variety of pathways. Many studies have explored the effects of microvessel alterations in the NP, annulus fibrosus, cartilaginous endplates, and bony endplates on the local microenvironment through inflammation, apoptosis, and senescence. Studies also elucidated the important roles of microvessel alterations in the process of IDD, as well as conducted in-depth explorations of cytokines and biologics that can inhibit or promote the ingrowth of microvessels. Therefore, the present manuscript reviews the published literature on the effects of microvascular changes on IVD to summarize the roles of microvessels in IVD and elaborate on the mechanisms of action that promote or inhibit de novo microvessel formation in IVD.

A Case Report: The Effects of Photobiomodulation Therapy and Amniotic Fluid Gel on a Severe Diabetic Foot Ulcer

Introduction: Diabetic patients frequently experience a serious complication known as impaired wound healing, which increases the likelihood of foot infection and limb amputation. Investigators have been looking for novel methods to treat diabetic foot ulcers (DFUs) recently. Case Report: A 75-year-old woman with type one diabetes mellitus (DM) has been accepted. There was a sizable (40 cm2 full-thickness cutaneous wound) in the plantar part of her right foot (Wagner Ulcer Grade Classification System: grade 3) which had not been treated by the usual treatment for DFUs. In this present case, we used amniotic fluid gel (AF gel) and photobiomodulation therapy (PBMT) (400 mW/cm2; 810 nm, once a week for 16 weeks) to treat and speed up the healing of a harsh DFU. The size of the ulcer area significantly decreased as combination therapy progressed, and within 16 weeks, the wound was healed and the pain was reduced. Conclusion: This revealed contextual analysis demonstrated the useful effect of the mix of PBMT and AF gel on a serious DFU. To confirm the findings, we recommend conducting additional clinical trials in a clinical setting. In addition, it is recommended that additional research using preclinical models uncover the mechanism of action of the combination therapy.

Molecular immunological mechanisms of impaired wound healing in diabetic foot ulcers (DFU), current therapeutic strategies and future directions

Diabetic foot ulcer (DFU) is a foremost cause of amputation in diabetic patients. Consequences of DFU include infections, decline in limb function, hospitalization, amputation, and in severe cases, death. Immune cells including macrophages, regulatory T cells, fibroblasts and other damage repair cells work in sync for effective healing and in establishment of a healthy skin barrier post-injury. Immune dysregulation during the healing of wounds can result in wound chronicity. Hyperglycemic conditions in diabetic patients influence the pathophysiology of wounds by disrupting the immune system as well as promoting neuropathy and ischemic conditions, making them difficult to heal. Chronic wound microenvironment is characterized by increased expression of matrix metalloproteinases, reactive oxygen species as well as pro-inflammatory cytokines, resulting in persistent inflammation and delayed healing. Novel treatment modalities including growth factor therapies, nano formulations, microRNA based treatments and skin grafting approaches have significantly augmented treatment efficiency, demonstrating creditable efficacy in clinical practices. Advancements in local treatments as well as invasive methodologies, for instance formulated wound dressings, stem cell applications and immunomodulatory therapies have been successful in targeting the complex pathophysiology of chronic wounds. This review focuses on elucidating the intricacies of emerging physical and non-physical therapeutic interventions, delving into the realm of advanced wound care and comprehensively summarizing efficacy of evidence-based therapies for DFU currently available.

Extracellular Vesicles Derived from H2O2-Stimulated Adipose-Derived Stem Cells Alleviate Senescence in Diabetic Bone Marrow Mesenchymal Stem Cells and Restore Their Osteogenic Capacity

Introduction

Autologous stem cell transplantation has emerged as a promising strategy for bone repair. However, the osteogenic potential of mesenchymal stem cells derived from diabetic patients is compromised, possibly due to hyperglycemia-induced senescence. The objective of this study was to assess the preconditioning effects of extracellular vesicles derived from H2O2-stimulated adipose-derived stem cells (ADSCs) and non-modified ADSCs on the osteogenic potential of diabetic bone marrow mesenchymal stem cells (BMSCs).

Methods

Sprague-Dawley (SD) rats were experimentally induced into a diabetic state through a high-fat diet followed by an injection of streptozotocin, and diabetic BMSCs were collected from the bone marrow of these rats. Extracellular vesicles (EVs) were isolated from the conditioned media of ADSCs, with or without hydrogen peroxide (H2O2) preconditioning, using density gradient centrifugation. The effects of H2O2 preconditioning on the morphology, marker expression, and particle size of the EVs were analyzed. Furthermore, the impact of EV-pretreatment on the viability, survivability, migration ability, osteogenesis, cellular senescence, and oxidative stress of diabetic BMSCs was examined. Moreover, the expression of the Nrf2/HO-1 pathway was also assessed to explore the underlying mechanism. Additionally, we transplanted EV-pretreated BMSCs into calvarial defects in diabetic rats to assess their in vivo bone formation and anti-senescence capabilities.

Results

Our study demonstrated that pretreatment with EVs from ADSCs significantly improved the viability, senescence, and osteogenic differentiation potential of diabetic BMSCs. Moreover, in-vitro experiments revealed that diabetic BMSCs treated with H2O2-activated EVs exhibited increased viability, reduced senescence, and enhanced osteogenic differentiation compared to those treated with non-modified EVs. Furthermore, when transplanted into rat bone defects, diabetic BMSCs treated with H2O2-activated EVs showed improved bone regeneration potential and enhanced anti-senescence function t compared to those treated with non-modified EVs. Both H2O2-activated EVs and non-modified EVs upregulated the expression of the Nrf2/HO-1 pathway in diabetic BMSCs, however, the promoting effect of H2O2-activated EVs was more pronounced than that of non-modified EVs.

Conclusion

Extracellular vesicles derived from H2O2-preconditioned ADSCs mitigated senescence in diabetic BMSCs and enhanced their bone regenerative functions via the activation of the Nrf2/HO-1 pathway.

Diabetes in spotlight: current knowledge and perspectives of photobiomodulation utilization

Introduction

Diabetes is a global health concern characterized by chronic hyperglycemia resulting from insulinopenia and/or insulin resistance. The rising prevalence of diabetes and its associated complications (ulcers, periodontitis, healing of bone defect, neuropathy, retinopathy, cardiopathy and nephropathy) necessitate innovative therapeutic approaches. Photobiomodulation (PBM), involves exposing tissues and cells to low-energy light radiation, leading to biological effects, largely via mitochondrial activation.

Methods

This review evaluates preclinical and clinical studies exploring the potential of PBM in diabetes and its complications, as well all clinical trials, both planned and completed, available on ClinicalTrials database.

Results

This review highlights the variability in PBM parameters across studies, hindering consensus on optimal protocols. Standardization of treatment parameters and rigorous clinical trials are needed to unlock PBM's full therapeutic potential. 87 clinical trials were identified that investigated PBM in diabetes mellitus (with 5,837 patients planned to be treated with PBM). Clinical trials assessing PBM effects on diabetic neuropathy revealed pain reduction and potential quality of life improvement. Studies focusing on wound healing indicated encouraging results, with PBM enhancing angiogenesis, fibroblast proliferation, and collagen density. PBM's impact on diabetic retinopathy remains inconclusive however, requiring further investigation. In glycemic control, PBM exhibits positive effects on metabolic parameters, including glucose tolerance and insulin resistance.

Conclusion

Clinical studies have reported PBM-induced reductions in fasting and postprandial glycemia without an increased hypoglycemic risk. This impact of PBM may be related to its effects on the beta cells and islets in the pancreas. Notwithstanding challenges, PBM emerges as a promising adjunctive therapy for managing diabetic neuropathy, wound healing, and glycemic control. Further investigation into its impact on diabetic retinopathy and muscle recovery is warranted.

Photobiomodulation preconditioned diabetic adipose derived stem cells with additional photobiomodulation: an additive approach for enhanced wound healing in diabetic rats with a delayed healing wound

In this preclinical investigation, we examined the effects of combining preconditioned diabetic adipose-derived mesenchymal stem cells (AD-MSCs) and photobiomodulation (PBM) on a model of infected ischemic delayed healing wound (injury), (IIDHWM) in rats with type I diabetes (TIDM). During the stages of wound healing, we examined multiple elements such as stereology, macrophage polarization, and the mRNA expression levels of stromal cell-derived factor (SDF)-1α, vascular endothelial growth factor (VEGF), hypoxia-induced factor 1α (HIF-1α), and basic fibroblast growth factor (bFGF) to evaluate proliferation and inflammation. The rats were grouped into: (1) control group; (2) diabetic-stem cells were transversed into the injury site; (3) diabetic-stem cells were transversed into the injury site then the injury site exposed to PBM; (4) diabetic stem cells were preconditioned with PBM and implanted into the wound; (5) diabetic stem cells were preconditioned with PBM and transferred into the injury site, then the injury site exposed additional PBM. While on both days 4, and 8, there were advanced histological consequences in groups 2-5 than in group 1, we found better results in groups 3-5 than in group 2 (p < 0.05). M1 macrophages in groups 2-5 were lower than in group 1, while groups 3-5 were reduced than in group 2 (p < 0.01). M2 macrophages in groups 2-5 were greater than in group 1, and groups 3-5 were greater than in group 2. (p ≤ 0.001). Groups 2-5 revealed greater expression levels of bFGF, VEGF, SDF- 1α, and HIF- 1α genes than in group 1 (p < 0.001). Overall group 5 had the best results for histology (p < 0.05), and macrophage polarization (p < 0.001). AD-MSC, PBM, and AD-MSC + PBM treatments all enhanced the proliferative stage of injury repairing in the IIDHWM in TIDM rats. While AD-MSC + PBM was well than the single use of AD-MSC or PBM, the best results were achieved with PBM preconditioned AD-MSC, plus additional PBM of the injury.

Progress and application of adipose-derived stem cells in the treatment of diabetes and its complications

Diabetes mellitus (DM) is a serious chronic metabolic disease that can lead to many serious complications, such as cardiovascular disease, retinopathy, neuropathy, and kidney disease. Once diagnosed with diabetes, patients need to take oral hypoglycemic drugs or use insulin to control blood sugar and slow down the progression of the disease. This has a significant impact on the daily life of patients, requiring constant monitoring of the side effects of medication. It also imposes a heavy financial burden on individuals, their families, and even society as a whole. Adipose-derived stem cells (ADSCs) have recently become an emerging therapeutic modality for DM and its complications. ADSCs can improve insulin sensitivity and enhance insulin secretion through various pathways, thereby alleviating diabetes and its complications. Additionally, ADSCs can promote tissue regeneration, inhibit inflammatory reactions, and reduce tissue damage and cell apoptosis. The potential mechanisms of ADSC therapy for DM and its complications are numerous, and its extensive regenerative and differentiation ability, as well as its role in regulating the immune system and metabolic function, make it a powerful tool in the treatment of DM. Although this technology is still in the early stages, many studies have already proven its safety and effectiveness, providing new treatment options for patients with DM or its complications. Although based on current research, ADSCs have achieved some results in animal experiments and clinical trials for the treatment of DM, further clinical trials are still needed before they can be applied in a clinical setting.

The Effect of Mesenchymal Stem Cells on the Wound Infection

Wound infection often requires a long period of care and an onerous treatment process. Also, the rich environment makes the wound an ideal niche for microbial growth. Stable structures, like biofilm, and drug-resistant strains cause a delay in the healing process, which has become one of the important challenges in wound treatment. Many studies have focused on alternative methods to deal the wound infections. One of the novel and highly potential ways is mesenchymal stromal cells (MSCs). MSCs are mesoderm-derived pluripotent adult stem cells with the capacity for self-renewal, multidirectional differentiation, and immunological control. Also, MSCs have anti-inflammatory and antiapoptotic effects. MScs, as pluripotent stromal cells, differentiate into many mature cells. Also, MSCs produce antimicrobial compounds, such as antimicrobial peptides (AMP), as well as secrete immune modulators, which are two basic features considered in wound healing. Despite the advantages, preserving the structure and activity of MSCs is considered one of the most important points in the treatment. MSCs' antimicrobial effects on microorganisms involved in wound infection have been confirmed in various studies. In this review, we aimed to discuss the antimicrobial and therapeutic applications of MSCs in the infected wound healing processes.

Assessing the role of combination of stem cell and light-based treatments on skin wound repair: A meta-analysis

The meta-analysis aims to evaluate and compare the impact of the combination of stem cells (SCs) and light-based treatments (LBTs) on skin wound (SW) repair. Examinations comparing SCs to LBT with SCs for SW repair was among the meta-analysis from various languages that met the inclusion criteria. Using continuous random-effect models, the results of these investigations were examined, and the mean difference (MD) with 95% confidence intervals was computed (CIs). Seven examinations from 2012 to 2022 were recruited for the current analysis including 106 animals with SWs. Photobiomodulation therapy (PBT) plus SCs had a significantly higher wound closure rate (WCR) (MD, 9.08; 95% CI, 5.55-12.61, p < 0.001) compared to SCs in animals with SWs. However, no significant difference was found between PBT plus SCs and SCs on wound tensile strength (WTS) (MD, 2.01; 95% CI, -0.42 to 4.44, p = 0.10) in animals with SWs. The examined data revealed that PBT plus SCs had a significantly higher WCR, however, no significant difference was found in WTS compared to SCs in animals with SWs. Nevertheless, caution should be exercised while interacting with its values since all the chosen examinations were found with a low sample size and a low number of examinations were found for the comparisons studied for the meta-analysis.

Physical therapy in diabetic foot ulcer: Research progress and clinical application

Diabetes foot ulcer (DFU) is one of the most intractable complications of diabetes and is related to a number of risk factors. DFU therapy is difficult and involves long-term interdisciplinary collaboration, causing patients physical and emotional pain and increasing medical costs. With a rising number of diabetes patients, it is vital to figure out the causes and treatment techniques of DFU in a precise and complete manner, which will assist alleviate patients' suffering and decrease excessive medical expenditure. Here, we summarised the characteristics and progress of the physical therapy methods for the DFU, emphasised the important role of appropriate exercise and nutritional supplementation in the treatment of DFU, and discussed the application prospects of non-traditional physical therapy such as electrical stimulation (ES), and photobiomodulation therapy (PBMT) in the treatment of DFU based on clinical experimental records in ClinicalTrials.gov.

The stereological, immunohistological, and gene expression studies in an infected ischemic wound in diabetic rats treated by human adipose-derived stem cells and photobiomodulation

We investigated the impacts of photobiomodulation (PBM) and human allogeneic adipose-derived stem cells (ha-ADS) together and or alone applications on the stereological parameters, immunohistochemical characterizing of M1 and M2 macrophages, and mRNA levels of hypoxia-inducible factor (HIF-1α), basic fibroblast growth factor (bFGF), vascular endothelial growth factor-A (VEGF-A) and stromal cell-derived factor-1α (SDF-1α) on inflammation (day 4) and proliferation phases (day 8) of repairing tissues in an infected delayed healing and ischemic wound model (IDHIWM) in type 1 diabetic (DM1) rats. DM1 was created in 48 rats and an IDHIWM was made in all of them, and they were distributed into 4 groups. Group1 = control rats with no treatment. Group2 = rats received (10 × 100000 ha-ADS). Group3 = rats exposed to PBM (890 nm, 80 Hz, 3.46 J/cm2). Group4 = rats received both PBM and ha-ADS. On day 8, there were significantly higher neutrophils in the control group than in other groups (p < 0.01). There were substantially higher macrophages in the PBM + ha-ADS group than in other groups on days 4 and 8 (p < 0.001). Granulation tissue volume, on both days 4 and 8, was meaningfully greater in all treatment groups than in the control group (all, p = 0.000). Results of M1 and M2 macrophage counts of repairing tissue in the entire treatment groups were considered preferable to those in the control group (p < 0.05). Regarding stereological and macrophage phenotyping, the results of the PBM + ha-ADS group were better than the ha-ADS and PBM groups. Results of the tested gene expression of repairing tissue on inflammation and proliferation steps in PBM and PBM + ha-ADS groups were meaningfully better than the control and ha-ADS groups (p < 0.05). We showed that PBM, ha-ADS, and PBM plus ha-ADS, hastened the proliferation step of healing in an IDHIWM in rats with DM1 by regulation of the inflammatory reaction, macrophage phenotyping, and augmented granulation tissue formation. In addition PBM and PBM plus ha-ADS protocols hastened and increased mRNA levels of HIF-1α, bFGF, SDF-1α, and VEGF-A. Totally, in terms of stereological and immuno-histological tests, and also gene expression HIF-1α and VEGF-A, the results of PBM + ha-ADS were superior (additive) to PBM, and ha-ADS alone treatments.

An Update on Adipose-Derived Stem Cells for Regenerative Medicine: Where Challenge Meets Opportunity

Over the last decade, adipose-derived stem cells (ADSCs) have attracted increasing attention in the field of regenerative medicine. ADSCs appear to be the most advantageous cell type for regenerative therapies owing to their easy accessibility, multipotency, and active paracrine activity. This review highlights current challenges in translating ADSC-based therapies into clinical settings and discusses novel strategies to overcome the limitations of ADSCs. To further establish ADSC-based therapies as an emerging platform for regenerative medicine, this review also provides an update on the advancements in this field, including fat grafting, wound healing, bone regeneration, skeletal muscle repair, tendon reconstruction, cartilage regeneration, cardiac repair, and nerve regeneration. ADSC-based therapies are expected to be more tissue-specific and increasingly important in regenerative medicine.

Combined Use of Photobiomodulation and Curcumin-Loaded Iron Oxide Nanoparticles Significantly Improved Wound Healing in Diabetic Rats Compared to Either Treatment Alone

Introduction: Here, we assess the therapeutic effects of photobiomodulation (PBM) and curcumin (CUR)-loaded superparamagnetic iron oxide nanoparticles (SPIONs), alone or together, on the maturation step of a type 1 diabetes (DM1) rat wound model. Methods: Full-thickness wounds were inflicted in 36 rats with diabetes mellitus (DM) induced by the administration of streptozotocin (STZ). The rats were randomly allocated to four groups. Group one was untreated (control); group two received CUR; group 3 received PBM (890 nm, 80 Hz, 0.2 J/cm2); group 4 received a combination of PBM plus CUR. On days 0, 4, 7, and 15, we measured microbial flora, wound closure fraction, tensile strength, and stereological analysis. Results: All treatment groups showed a substantial escalation in the wound closure rate, a substantial reduction in the count of methicillin-resistant Staphylococcus aureus (MRSA), a substantial improvement in wound strength, a substantially improvement in stereological parameters compared to the control group, however, the PBM+CUR group was superior to the other treatment groups (all, P≤0.05). Conclusion: All treatment groups showed significantly improved wound healing in the DM1 rat model. However, the PBM+CUR group was superior to the other treatment groups and the control group in terms of wound strength and stereological parameters.

Photobiomodulation, alone or combined with adipose-derived stem cells, reduces inflammation by modulation of microRNA-146a and interleukin-1ß in a delayed-healing infected wound in diabetic rats

Diabetic wounds are categorized by chronic inflammation, leading to the development of diabetic foot ulcers, which cause amputation and death. Herewith, we examined the effect of photobiomodulation (PBM) plus allogeneic diabetic adipose tissue-derived stem cells (ad-ADS) on stereological parameters and expression levels of interleukin (IL)-1ß and microRNA (miRNA)-146a in the inflammatory (day 4) and proliferation (day 8) stages of wound healing in an ischemic infected (with 2×107 colony-forming units of methicillin-resistant Staphylococcus aureus) delayed healing wound model (IIDHWM) in type I diabetic (TIDM) rats. There were five groups of rats: group 1 control (C); group 2 (CELL) in which rat wounds received 1×106 ad-ADS; group 3 (CL) in which rat wounds received the ad-ADS and were subsequently exposed to PBM(890 nm, 80 Hz, 3.5 J/cm2, in vivo); group 4 (CP) in which the ad-ADS preconditioned by the PBM(630 nm + 810 nm, 0.05 W, 1.2 J/cm2, 3 times) were implanted into rat wounds; group 5 (CLP) in which the PBM preconditioned ad-ADS were implanted into rat wounds, which were then exposed to PBM. On both days, significantly better histological results were seen in all experimental groups except control. Significantly better histological results were observed in the ad-ADS plus PBM treatment correlated to the ad-ADS alone group (p<0.05). Overall, PBM preconditioned ad-ADS followed by PBM of the wound showed the most significant improvement in histological measures correlated to the other experimental groups (p<0.05). On days 4 and 8, IL-1 β levels of all experimental groups were lower than the control group; however, on day 8, only the CLP group was different (p<0.01). On day 4, miR-146a expression levels were substantially greater in the CLP and CELL groups correlated to the other groups, on day 8 miR-146a in all treatment groups was upper than C (p<0.01). ad-ADS plus PBM, ad-ADS, and PBM all improved the inflammatory phase of wound healing in an IIDHWM in TIDM1 rats by reducing inflammatory cells (neutrophils, macrophages) and IL-1ß, and increasing miRNA-146a. The ad-ADS+PBM combination was better than either ad-ADS or PBM alone, because of the higher proliferative and anti-inflammatory effects of the PBM+ad-ADS regimen.

Injection of stem cells derived from allogeneic adipose tissue, a new strategy for the treatment of diabetic wounds

A diabetic wound is one of the major complications of Diabetes mellitus. Considering the impact of these wounds on the health and quality of life of diabetic patients, the need for a suitable treatment is essential. Adipose-derived stem cells (ASCs) play a role in healing diabetic wounds. The purpose of this study is to examine the effect of ASCs on skin wound healing in diabetic rats. Rats were divided into three groups, diabetics treated with ASCs, non-diabetic, and diabetic (treated with phosphate-buffered saline). Skin wounds and its margin were examined to measure the level of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) and histopathological examinations on three, six, and nine days after wound formation and treatment. As a result, the administration of ASCs can reduce the healing time of skin wounds in diabetic rats by controlling inflammation and increasing angiogenesis.

Photobiomodulation Therapy Improves Inflammatory Responses by Modifying Stereological Parameters, microRNA-21 and FGF2 Expression

Introduction: Photobiomodulation treatment (PBMT) is a relatively invasive method for treating wounds. An appropriate type of PBMT can produce desired and directed cellular and molecular processes. The aim of this study was to investigate the impacts of PBMT on stereological factors, bacterial count, and the expression of microRNA-21 and FGF2 in an infected, ischemic, and delayed wound healing model in rats with type one diabetes mellitus. Methods: A delayed, ischemic, and infected wound was produced on the back skin of all 24 DM1 rats. Then, they were put into 4 groups at random (n=6 per group): 1=Control group day4 (CGday4); 2=Control group day 8 (CGday8); 3=PBMT group day4 (PGday4), in which the rats were exposed to PBMT and killed on day 4; 4=PBMT group day8 (PGday8), in which the rats received PBMT and they were killed on day 8. The size of the wound, the number of microbial colonies, stereological parameters, and the expression of microRNA-21 and FGF2 were all assessed in this study throughout the inflammation (day 4) and proliferation (day 8) stages of wound healing. Results: On days 4 and 8, we discovered that the PGday4 and PGday8 groups significantly improved stereological parameters in comparison with the same CG groups. In terms of ulcer area size and microbiological counts, the PGday4 and PGday8 groups performed much better than the same CG groups. Simultaneously, the biomechanical findings in the PGday4 and PGday8 groups were much more extensive than those in the same CG groups. On days 4 and 8, the expression of FGF2 and microRNA-21 was more in all PG groups than in the CG groups (P<0.01). Conclusion: PBMT significantly speeds up the repair of ischemic and MARS-infected wounds in DM1 rats by lowering microbial counts and modifying stereological parameters, microRNA-21, and FGF2 expression.

Advanced polymer hydrogels that promote diabetic ulcer healing: mechanisms, classifications, and medical applications

Diabetic ulcers (DUs) are one of the most serious complications of diabetes mellitus. The application of a functional dressing is a crucial step in DU treatment and is associated with the patient's recovery and prognosis. However, traditional dressings with a simple structure and a single function cannot meet clinical requirements. Therefore, researchers have turned their attention to advanced polymer dressings and hydrogels to solve the therapeutic bottleneck of DU treatment. Hydrogels are a class of gels with a three-dimensional network structure that have good moisturizing properties and permeability and promote autolytic debridement and material exchange. Moreover, hydrogels mimic the natural environment of the extracellular matrix, providing suitable surroundings for cell proliferation. Thus, hydrogels with different mechanical strengths and biological properties have been extensively explored as DU dressing platforms. In this review, we define different types of hydrogels and elaborate the mechanisms by which they repair DUs. Moreover, we summarize the pathological process of DUs and review various additives used for their treatment. Finally, we examine the limitations and obstacles that exist in the development of the clinically relevant applications of these appealing technologies. This review defines different types of hydrogels and carefully elaborate the mechanisms by which they repair diabetic ulcers (DUs), summarizes the pathological process of DUs, and reviews various bioactivators used for their treatment.

Effects of photobiomodulation on mitochondrial function in diabetic adipose-derived stem cells in vitro

Herein are reported the effects of photobiomodulation (PBM) on adenosine triphosphate (ATP) and reactive oxygen species (ROS) quantification and mitochondria membrane potential (MMP) of the mitochondria of diabetic adipose-derived stem cells (ADSCs) in vitro. Additionally, the expression of PTEN-induced kinase 1 (PINK1) and RBR E3 ubiquitin-protein ligase (PARKIN) genes, which are involved in mitochondrial quality, were quantified. First, type one diabetes was induced in 10 rats. The rats were then kept for 1 month, after which fat tissue was excised from subcutaneous regions, and stem cells were selected from the fat, characterized as ADSC, and cultivated and increased in elevated sugar conditions in vitro; these samples were considered diabetic-ADSC. Two groups were formed, namely, diabetic-control-ADSC and PBM-diabetic-ADSC. ATP, ROS quantification, and MMP of mitochondria of diabetic ADSCs in vitro were measured, and the expression of PINK1 and Parkin genes was quantified in vitro. The results revealed that PBM significantly increased ATP quantification (p = 0.05) and MMP activity (p = 0.000) in diabetic-ADSCs in vitro compared to the control diabetic-ADSCs; however, it significantly decreased ROS quantification (p = 0.002) and PINK1(p = 0.003) and PARKIN gene expression (p = 0.046) in diabetic-ADSCs. The current findings indicate for the first time that PBM has the potential to maintain the function and quality of mitochondrial diabetic-ADSCs by significantly increasing ATP quantification and MMP activity in diabetic-ADSCs in vitro while significantly decreasing ROS quantification and PINK1 and PARKIN gene expression, making PBM an attractive candidate for use in improving the efficacy of autologous stem cell remedies for diabetic patients with infected diabetic foot ulcers.

Efficacy of autologous mesenchymal stromal cell treatment for chronic degenerative musculoskeletal conditions in dogs: A retrospective study

Introduction

The objective of this study was to retrospectively analyze clinical data from a referral regenerative medicine practice, to investigate the efficacy of autologous mesenchymal stromal cells (MSC) in 245 dogs deemed unresponsive to conventional treatment by their referring vet.

Methods

Diagnostic imaging [radiology and musculoskeletal ultrasound (MSK-US)] identified musculoskeletal pathology holistically. MSCs, produced according to current guidelines, were initially administered with PRP by targeted injection to joints and/or tendons, with a second MSC monotherapy administered 12 weeks later to dogs with severe pathology and/or previous elbow arthroscopic interventions. Dogs with lumbosacral disease received epidural MSCs with additional intravenous MSCs administered to dogs with spondylosis of the cervical, thoracic and lumbar spine. All dogs received laser therapy at 10 J/cm2 at the time of treatment and for 5 sessions thereafter. Objective outcome measures (stance analysis, range of joint motion, pressure algometry) and validated subjective outcome measures (owner reported VetMetrica HRQL™ and veterinary pain and quality of life impact scores) were used to investigate short and long-term (6-104 weeks) efficacy. Outcome data were collected at predetermined time windows (0-6, 7-12, 13-18, 19-24, 25-48, 49-78, 79-104) weeks after initial treatment.

Results

There were statistically significant improvements in post compared with pre-treatment measures at all time windows in stance analysis, shoulder and hip range of motion, lumbosacral pressure algometry, and to 49-78 weeks in carpus and elbow range of motion. Improvements in 4 domains of quality of life as measured by VetMetricaTM were statistically significant, as were scores in vet-assessed pain and quality of life impact. In dogs receiving one initial treatment the mean time before a second treatment was required to maintain improvements in objective measures was 451 days. Diagnostic imaging confirmed the regenerative effects of MSCs in tendinopathies by demonstrating resolution of abnormal mineralization and restoration of normal fiber patterns.

Discussion

This represents the first study using "real-world" data to show that cell-based therapies, injected into multiple areas of musculoskeletal pathology in a targeted holistic approach, resulted in rapid and profound positive effects on the patient's pain state and quality of life which was maintained with repeat treatment for up to 2 years.

LPS-pretreatment adipose-derived mesenchymal stromal cells promote wound healing in diabetic rats by improving angiogenesis

Mesenchymal stem cells (MSCs) play a key role in wound healing, and the advantages of pretreated MSCs in wound healing have previously been reported. In the present study, we investigated the impact of LPS pretreated human adipose-derived MSCs on skin wound healing in diabetic rats. We found that some improvements occurred through improving angiogenesis. Then, we scrutinized the impact of lipopolysaccharide (LPS) treatment on human adipose-derived MSCs in a high-glucose (HG) medium, as an in vitro diabetic model. In vivo findings revealed significant improvements in epithelialization and angiogenesis of diabetic wounds which received LPS pre-MSCs. Particularly, LPS pre-MSCs-treated diabetic wounds reached considerably higher percentages of wound closure. Also, the granulation tissue of these wounds had higher pronounced epithelialization and more vascularization compared with PBS-treated and MSCs-treated diabetic ones by CD31, VEGF, CD90, collagen 1, and collagen 3 immunostaining. Western-blots analyses indicated that LPS pre-MSCs led to the upregulation of vascular endothelial growth factor (VEGF) and DNMT1. In addition, significantly higher cell viability (proliferation/colonie), and elevated VEGF and DNMT1 protein expression were observed when MSCs were treated with LPS (10 ng/ml, 6 h) in HG culture media. Based on these findings, it is suggested that LPS pre-MSCs could promote wound repair and skin regeneration, in some major processes, via the improvement of cellular behaviors of MSCs in the diabetic microenvironment. The beneficial advantages of LPS treated with mesenchymal stem cells on wound healing may lead to establishing a novel approach as an alternative therapeutic procedure to cure chronic wounds in diabetic conditions.

Potential of stem cells for treating infected Diabetic Foot Wounds and Ulcers: a systematic review

Infected diabetic foot ulcers (iDFUs) cause great concern, as they generally heal poorly and are precursive of diabetic-related foot amputation and even death. Scientists have tested various techniques in attempts to ascertain the best treatment for iDFUs; however, the results have remained inconclusive. Stem cell therapy (SCT) appears to improve iDFU through its antimicrobial impacts, yet cogent information regarding the repair of iDFUs with SCT is lacking. Herein, published articles are evaluated to report coherent information about the antimicrobial effects of SCT on the repair of iDFUs in diabetic animals and humans. In this systematic review, we searched the Scopus, Medline, Google Scholar, and Web of Science databases for relevant full-text English language articles published from 2000 to 2022 that described stem cell antimicrobial treatments, infected diabetic wounds, or ulcers. Ultimately, six preclinical and five clinical studies pertaining to the effectiveness of SCT on healing infected diabetic wounds or ulcers were selected. Some of the human studies confirmed that SCT is a promising therapy for diabetic wounds and ulcers. Notably, more controlled studies performed on animal models revealed that stem cells combined with a biostimulator such as photobiomodulation decreased colony forming units and hastened healing in infected diabetic wounds. Moreover, stem cells alone had lower therapeutic impact than when combined with a biostimulant.

The Combined Effects of a Methacrylate Powder Dressing (Altrazeal Powder) and Photobiomodulation Therapy on the Healing of a Severe Diabetic Foot Ulcer in a Diabetic Patient: A Case Report

Weakened wound healing is a popular, severe complication of patients with diabetes which poses a risk for foot infection and amputation. Researchers have searched for new treatments for treating diabetic foot ulcers (DFUs) in recent years. In this case report, for the first time, we applied photobiomodulation therapy (PBMT) and Altrazeal powder together to treat a severe case of DFU in a 47-year-old woman who was suffering from type 1 diabetes. Along with the progress of combination therapy, we observed that the ulcer area was significantly reduced, and the wound healed within 16 weeks. Furthermore, dermatitis and purulent secretion were treated, and the pain was reduced. This reported case study indicated the beneficial effect of the combination of PBMT and Altrazeal powder for the healing of a severe DFU in a patient with type one diabetes. The combined application of PBMT plus Altrazeal powder demonstrated an additive effect. Further clinical trials in the clinical setting are suggested to validate the results further. Besides, more studies in preclinical models are suggested to find the mechanism of the action of combination therapy.

Promoting Immortalized Adipose-Derived Stem Cell Transdifferentiation and Proliferation into Neuronal-Like Cells through Consecutive 525 nm and 825 nm Photobiomodulation

Neuronal cells can be generated from adipose-derived stem cells (ADSCs) through biological or chemical inducers. Research has shown that this process may be optimized by the introduction of laser irradiation in the form of photobiomodulation (PBM) to cells. This in vitro study is aimed at generating neuronal-like cells with inducers, chemical or biological, and at furthermore treating these transdifferentiating cells with consecutive PBM of a 525 nm green (G) laser and 825 nm near-infrared (NIR) laser light with a fluence of 10 J/cm². Cells were exposed to induction type 1 (IT1): 3-isobutyl-1-methylxanthine (IBMX) (0.5 mM)+indomethacin (200 μM)+insulin (5 μg/ml) for 14 days, preinduced with β-mercaptoethanol (BME) (1 mM) for two days, and then incubated with IT2: β-hydroxyanisole (BHA) (100 μM)+retinoic acid (RA) (10-6 M)+epidermal growth factor (EGF) (10 ng/ml)+basic fibroblast growth factor (bFGF) (10 ng/ml) for 14 days and preinduced with β-mercaptoethanol (BME) (1 mM) for two days and then incubated with indomethacin (200 μM)+RA (1 μM)+forskolin (10 μM) for 14 days. The results were evaluated through morphological observations, viability, proliferation, and migration studies, 24 h, 48 h, and 7 days post-PBM. The protein detection of an early neuronal marker, neuron-specific enolase (NSE), and late, ciliary neurotrophic factor (CNTF), was determined with enzyme-linked immunosorbent assays (ELISAs). The genetic expression was also explored through real-time PCR. Results indicated differentiation in all experimental groups; however, cells that were preinduced showed higher proliferation and a higher differentiation rate than the group that was not preinduced. Within the preinduced groups, results indicated that cells treated with IT2 and consecutive PBM upregulated differentiation the most morphologically and physiologically.

Impact of photobiomodulation on macrophages and their polarization during diabetic wound healing: a systematic review

This review aims to providing essential information and the current knowledge about the potential role of macrophages, especially their M2 subtypes in different diabetic wounds both in clinical and pre-clinical models under the influence of photobiomodulation (PBM). The long-term goal is to advance the macrophage-based therapies to accelerate healing of diabetic foot ulcers. We reviewed all databases provided by PubMed, Google Scholar, Scopus, Web of Science, and Cochrane precisely from their dates of inception to 25/10/2021. The keywords of Diabetes mellitus diseases, wound healing, macrophage, and photobiomodulation or low-level laser therapy were used in this systematic review.A total of 438 articles were initially identified in pubmed.ncbi.nlm.nih.gov (15 articles), Google scholar (398 articles), Scopus (18 articles), and Web of Science (7 articles). Four hundred sixteen articles that remained after duplicate studies (22 articles) were excluded. After screening abstracts and full texts, 14 articles were included in our analysis. Among them, 4 articles were about the effect of PBM on macrophages in type 2 diabetes and also found 10 articles about the impact of PBM on macrophages in type 1 diabetes. The obtained data from most of the reviewed studies affirmed that the PBM alone or combined with other agents (e.g., stem cells) could moderate the inflammatory response and accelerate the wound healing process in pre-clinical diabetic wound models. However, only very few studies conducted the detailed functions of polarized macrophages and M2 subtypes in wound healing of diabetic models under the influence of PBM. Further pre-clinical and clinical investigations are still needed to investigate the role of M2 macrophages, especially its M2c subtype, in the healing processes of diabetic foot ulcers in clinical and preclinical settings.

Could Light-Based Technologies Improve Stem Cell Therapy for Skin Wounds? A Systematic Review and Meta-Analysis of Preclinical Studies

Several diseases or conditions cause dermatological disorders that hinder the process of skin repair. The search for novel technologies has inspired the combination of stem cell (SC) and light-based therapies to ameliorate skin wound repair. Herein, we systematically revised the impact of photobiomodulation therapy (PBM) combined with SCs in animal models of skin wounds and quantitatively evaluated this effect through a meta-analysis. For inclusion, SCs should be irradiated in vitro or in vivo, before or after being implanted in animals, respectively. The search resulted in nine eligible articles, which were assessed for risk of bias. For the meta-analysis, studies were included only when PBM was applied in vivo, five regarding wound closure, and three to wound strength. Overall, a positive influence of SC+PBM on wound closure (MD: 9.69; 95%CI: 5.78 to 13.61, p<0.00001) and strength (SMD: 1.7, 95%CI: 0.68 to 2.72, p=0.001) was detected, although studies have shown moderate to high heterogeneity and a lack of information regarding some bias domains. Altogether, PBM seems to be an enabling technology able to be applied post-implantation of SCs for cutaneous regeneration. Our findings may guide future laboratory and clinical studies in hopes of offering wound care patients a better quality of life.

The 532 nm Laser Treatment Promotes the Proliferation of Tendon-Derived Stem Cells and Upregulates Nr4a1 to Stimulate Tenogenic Differentiation

Objective: This study aimed to verify the effect of photobiomodulation therapy (PBMT) with a wavelength of 532 nm on the proliferation and differentiation of tendon-derived stem cells (TDSCs) of Sprague-Dawley (SD) rats. Background: The combination of PBMT and stem cell transplantation with TDSCs provides a new treatment strategy for tendon injury. Nevertheless, the effect of PBMT on the biological behavior of TDSCs and its internal mechanisms remain unclear. Methods: TDSCs were isolated from Achilles tendons of SD rats and identified by cell morphology and flow cytometric analysis. Energy density gradient experiment was performed to determine the ideal energy. Then, TDSCs were treated with PBMT using a wavelength of 532 nm at a fluence of 15 J/cm² in 532 nm laser group, and the TDSC in control group were not treated with 532 nm laser. Cell response after irradiation was observed to ascertain cell morphology and cell proliferation in the 532 nm laser group and the control group. The RNA expression levels of the key genes of TDSC differentiation, including scleraxis (Scx), tenomodulin (Tnmd), Mohawk homeobox (Mkx), Decorin (Dcn), peroxisome proliferator-activated receptor gamma (PPARγ), SRY-box transcription factor 9 (Sox9), and RUNX family transcription factor 2 (Runx2), were detected by reverse transcription-polymerase chain reaction. Then, gene chip microarray was used to detect the expression of differential genes after 532 nm laser intervention in TDSCs, and the target genes were screened out to verify the role in this process in vitro and in vivo. Results: When the 532 nm laser energy density was 15 J/cm², the proliferation capacity of TDSCs was improved (2.73 ± 0.24 vs. 1.81 ± 0.71, p < 0.05), and the expression of genes related to tenogenic differentiation of TDSCs was significantly increased (p < 0.01). After RNA sequencing and bioinformatics analyses, we speculated that nuclear receptor subfamily 4 group A member 1 (Nr4a1) was involved in the tenogenic differentiation process of TDSCs regulated by 532 nm laser treatment. Subsequent experiments confirmed that Nr4a1 regulated the expression of the tenogenic differentiation genes Scx and Tnmd in TDSCs. Conclusions: A 532 nm laser with 15 J/cm² regulated the process of TDSC proliferation and upregulated Nr4a1 to stimulate tenogenic differentiation.

Stem Cells and Angiogenesis: Implications and Limitations in Enhancing Chronic Diabetic Foot Ulcer Healing

Nonhealing diabetic foot ulcers (DFUs) are a continuing clinical issue despite the improved treatment with wound debridement, off-loading the ulcer, medication, wound dressings, and preventing infection by keeping the ulcer clean. Wound healing is associated with granulation tissue formation and angiogenesis favoring the wound to enter the resolution phase of healing followed by healing. However, chronic inflammation and reduced angiogenesis in a hyperglycemic environment impair the normal healing cascade and result in chronically non-healing diabetic foot ulcers. Promoting angiogenesis is associated with enhanced wound healing and using vascular endothelial growth factors has been proven beneficial to promote neo-angiogenesis. However, still, nonhealing DFUs persist with increased risks of amputation. Regenerative medicine is an evolving branch applicable in wound healing with the use of stem cells to promote angiogenesis. Various studies have reported promising results, but the associated limitations need in-depth research. This article focuses on summarizing and critically reviewing the published literature since 2021 on the use of stem cells to promote angiogenesis and enhance wound healing in chronic non-healing DFUs.

Adipose-Derived Stem Cells for the Treatment of Diabetic Wound: From Basic Study to Clinical Application

Diabetic wounds significantly affect the life quality of patients and may cause amputation and mortality if poorly managed. Recently, a wide range of cell-based methods has emerged as novel therapeutic methods in treating diabetic wounds. Adipose-derived stem cells (ASCs) are considered to have the potential for widespread clinical application of diabetic wounds treatment in the future. This review summarized the mechanisms of ASCs to promote diabetic wound healing, including the promotion of immunomodulation, neovascularization, and fibro synthesis. We also review the current progress and limitations of clinical studies using ASCs to intervene in diabetic wound healing. New methods of ASC delivery have been raised in recent years to provide a standardized and convenient use of ASCs.

Indirect Application of Intense Pulsed Light Induces Therapeutic Effects on Experimental Murine Meibomian Gland Dysfunction

Purpose

To investigate the indirect effects of intense pulsed light (IPL) on morphological and pathological changes of the meibomian glands (MGs) in apolipoprotein E knockout (ApoE^–/–) mice and explore the underlying mechanisms.

Methods

ApoE^–/– mice were treated with or without IPL three times below the lower eyelids and MGs were not directly exposed to irradiation. The eyelids and ocular surface were observed under a stereoscope. The morphology of MGs was examined by photographing and hematoxylin and eosin staining. Lipid droplets in MGs were examined by Oil Red O staining. The ultrastructure of meibocytes and mitochondria was observed under transmission electron microscopy. The relative gene and protein expression in MGs of upper eyelids was determined by immunostaining, Western blot, and qRT–PCR.

Results

Three IPL treatments decreased the toothpaste-like plugging of orifices and thickening and irregularity of the upper and lower eyelid margins in ApoE^–/– mice. The morphology of some MGs improved after IPL treatments, accompanied by increased proliferation of acinar basal cells and decreased ductal keratinization. Furthermore, the accumulation of hyperchromatic lipid droplets in the acini increased, and the lipid droplets distributed in the cells around the acini were round and small. Compared with untreated ApoE^–/– mice, oxidative stress and apoptosis were downregulated by IPL treatment, accompanied by the improvements in mitochondrial structure. Further research showed that IPL treatments reduced the levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-17A, IL-6 in MGs and inactivated nuclear factor kappa B (NF-κ B).

Conclusion

Collectively, the results demonstrate that indirect effects of IPL can improve the structure and function of MGs and mitigate the progression of MGD, which may be related to the indirect effects of photobiomodulation.

Photobiomodulation Therapy: A New Light in the Treatment of Systemic Sclerosis Skin Ulcers

INTRODUCTION

Skin ulcers (SU) represent one of the most frequent manifestations of systemic sclerosis (SSc), occurring in almost 50% of scleroderma patients. SSc-SU are often particularly difficult to treat with conventional systemic and local therapies. In this study, a preliminary evaluation of the role and effectiveness of blue light photobiomodulation (PBM) therapy with EmoLED^® in the treatment of scleroderma skin ulcers (SSc-SU) was performed.

METHODS

We retrospectively analyzed 12 consecutive SSc patients with a total of 15 SU on finger hands. All patients were treated with adequate systemic therapy and local treatment for SU; after a standard skin ulcer bed preparation with debridement of all lesions, EmoLED^® was performed. All patients were locally treated every week during 2 months of follow-up; SU data were collected after 4 weeks (T4) and 8 weeks (T8). Eight SSc patients with comparable SU were also evaluated as controls.

RESULTS

The application of EmoLED^® in addition to debridement apparently produced faster healing of SU. Complete healing of SU was recorded in 41.6% cases during EmoLED^® treatment. Significant improvements in SU area, length, and width, wound bed, and related pain were observed in EmoLED^® patients from T0 to T8. Control subjects treated with standard systemic/local therapies merely showed an amelioration of SU area and width at the end of the follow-up. No procedural or post-procedural adverse events were reported.

CONCLUSIONS

The positive clinical results and the absence of side effects suggest that EmoLED^® could be a promising tool in the management of SSc-SU, with an interesting role to play in the healing process in addition to conventional systemic and local treatments.

Single Cell Effects of Photobiomodulation on Mitochondrial Membrane Potential and Reactive Oxygen Species Production in Human Adipose Mesenchymal Stem Cells

Photobiomodulation (PBM) has recently emerged in cellular therapy as a potent alternative in promoting cell proliferation, migration, and differentiation during tissue regeneration. Herein, a single-cell near-infrared (NIR) laser irradiation system (830 nm) and the image-based approaches were proposed for the investigation of the modulatory effects in mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS), and vesicle transport in single living human adipose mesenchymal stem cells (hADSCs). The irradiated-hADSCs were then stained with 2′,7′-dichlorodihydrofluorescein diacetate (H₂DCFDA) and Rhodamine 123 (Rh123) to represent the ΔΨm and ROS production, respectively, with irradiation in the range of 2.5–10 (J/cm²), where time series of bright-field images were obtained to determine the vesicle transport phenomena. Present results showed that a fluence of 5 J/cm² of PBM significantly enhanced the ΔΨm, ROS, and vesicle transport phenomena compared to the control group (0 J/cm²) after 30 min PBM treatment. These findings demonstrate the efficacy and use of PBM in regulating ΔΨm, ROS, and vesicle transport, which have potential in cell proliferation, migration, and differentiation in cell-based therapy.

Evaluation of the effects of preconditioned human stem cells plus a scaffold and photobiomodulation administration on stereological parameters and gene expression levels in a critical size bone defect in rats

We assessed the impact of photobiomodulation (PBM) plus adipose-derived stem cells (ASCs) during the anabolic and catabolic stages of bone healing in a rat model of a critical size femoral defect (CSFD) that was filled with a decellularized bone matrix (DBM). Stereological analysis and gene expression levels of bone morphogenetic protein 4 (BMP4), Runt-related transcription factor 2 (RUNX2), and stromal cell-derived factor 1 (SDF1) were determined. There were six groups of rats. Group 1 was the untreated control or DBM. Study groups 2-6 were treated as follows: ASC (ASC transplanted into DBM, then implanted in the CSFD); PBM (CSFD treated with PBM); irradiated ASC (iASC) (ASCs preconditioned with PBM, then transplanted into DBM, and implanted in the CSFD); ASC + PBM (ASCs transplanted into DBM, then implanted in the CSFD, followed by PBM administration); and iASC + PBM (the same as iASC, except CSFDs were exposed to PBM). At the anabolic step, all treatment groups had significantly increased trabecular bone volume (TBV) (24.22%) and osteoblasts (83.2%) compared to the control group (all, p = .000). However, TBV in group iASC + PBM groups were superior to the other groups (97.48% for osteoblast and 58.8% for trabecular bone volume) (all, p = .000). The numbers of osteocytes in ASC (78.2%) and iASC + PBM (30%) groups were remarkably higher compared to group control (both, p = .000). There were significantly higher SDF (1.5-fold), RUNX2 (1.3-fold), and BMP4 (1.9-fold) mRNA levels in the iASC + PBM group compared to the control and some of the treatment groups. At the catabolic step of bone healing, TBV increased significantly in PBM (30.77%), ASC + PBM (32.27%), and iASC + PBM (35.93%) groups compared to the control group (all, p = .000). There were significantly more osteoblasts and osteocytes in ASC (71.7%, 62.02%) (p = .002, p = .000); PBM (82.54%, 156%), iASC (179%, 23%), and ASC + PBM (108%, 110%) (all, p = .000), and iASC + PBM (79%, 100.6%) (p = .001, p = .000) groups compared to control group. ASC preconditioned with PBM in vitro plus PBM in vivo significantly increased stereological parameters and SDF1, RUNX2, and BMP4 mRNA expressions during bone healing in a CSFD model in rats.

The effect of photobiomodulation therapy on antioxidants and oxidative stress profiles of adipose derived mesenchymal stem cells in diabetic rats

We studied the effects of photobiomodulation therapy (PBMT) on adipose-derived mesenchymal stem cells (ADSCs) which were extracted from streptozotocin (STZ) induced diabetic rats. Adipose tissue was extracted from the hypodermis of diabetic rats, and diabetic ADSCs were extracted, characterized, and cultured. There were two in vitro groups: control-diabetic ADSCs, and PBMT-diabeticADSCs. We used 630 nm and 810 nm laser at 1.2 J/cm² with 3 applications 48 h apart. We measured cell viability, apoptosis, population doubling time (PDT), and reactive oxygen species (ROS) by flow cytometry. Gene expression of antioxidants, including cytosolic copper-zinc superoxide dismutase (SOD1), catalase (CAT), total antioxidant capacity (TAC), and oxidative stress biomarkers (NADPH oxidase 1 and 4) by quantitative real time (qRT) - PCR. In this study, data were analyzed using t-test. Viability of PBMT-diabetic- ADSC group was higher than control- diabetic-ADSC (p = 0.000). PDT and apoptosis of PBMT- diabetic-ADSC group were lower than control-diabetic -ADSC (p = 0.001, p = 0.02). SOD1 expression and TAC of PBMT- diabetic-ADSC group were higher than control -diabetic -ADSC (p = 0.018, p = 0.005). CAT of PBMT -diabetic-ADSC group was higher than control-diabetic -ADSC. ROS, NOX1, and NOX4 of PBMT- diabetic -ADSC group were lower than control-diabetic-ADSC (p = 0.002, p = 0.021, p = 0.017). PBMT may improve diabetic- ADSC function in vitro by increasing levels of cell viability, and gene expression of antioxidant agents (SOD1, CAT, and TAC), and significantly decreasing of levels of PDT, apoptosis, ROS, and gene expression of oxidative stress biomarkers (NOX1 and NOX4).

Simultaneous Treatment of Photobiomodulation and Demineralized Bone Matrix With Adipose-Derived Stem Cells Improve Bone Healing in an osteoporotic bone defect

Introduction: The ability of simultaneous treatment of critical-sized femoral defects (CSFDs) with photobiomodulation (PBM) and demineralized bone matrix (DBM) with or without seeded adipose-derived stem cells (ASCs) to induce bone reconstruction in ovariectomized induced osteoporotic (OVX) rats was investigated. Methods: The OVX rats with CSFD were arbitrarily separated into 6 groups: control, scaffold (S, DBM), S + PBM, S + alendronate (ALN), S + ASCs, and S + PBM + ASCs. Each group was assessed by cone beam computed tomography (CBCT) and histological examinations. Results: In the fourth week, CBCT and histological analyses revealed that the largest volume of new bone formed in the S + PBM and S + PBM + ASC groups. The S + PBM treatment relative to the S and S + ALN treatments remarkably reduced the CSFD (Mann-Whitney test, P = 0.009 and P = 0.01). Furthermore, S + PBM + ASCs treatment compared to the S and S + ALN treatments significantly decreased CSFD (Mann Whitney test, P = 0.01). In the eighth week, CBCT analysis showed that extremely enhanced bone regeneration occurred in the CSFD of the S + PBM group. Moreover, the CSFD in the S + PBM group was substantially smaller than S, S + ALN and S + ASCs groups (Mann Whitney test, P = 0.01, P = 0.02 and P = 0.009). Histological observations showed more new bone formation in the treated CSFD of S + PBM + ASCs and S + PBM groups. Conclusion: The PBM plus DBM with or without ASCs significantly enhanced bone healing in the CSFD in OVX rats compared to control, DBM alone, and ALN plus DBM groups. The PBM plus DBM with or without ASCs significantly decreased the CSFD area compared to either the solo DBM or ALN plus DBM treatments.

Effectiveness of preconditioned adipose-derived mesenchymal stem cells with photobiomodulation for the treatment of diabetic foot ulcers: a systematic review

The primary goal of this systematic review article was to provide an outline of the use of diabetic autologous adipose-derived mesenchymal stem cells (DAAD-MSCs) in the treatment of wounds and ulcers in animal models and patients with diabetes mellitus (DM). The secondary goal was to present the outcomes of pretreatment of diabetic adipose-derived mesenchymal stem cells (DAD-MSCs) with probable different agents in the treatment of diabetic foot ulcers (DFUs) and wounds. In view of possible clinical applications of AD-MSC-mediated cell therapy for DFUs, it is essential to evaluate the influence of DM on AD-MSC functions. Nevertheless, there are conflicting results about the effects of DAAD-MSCs on accelerating wound healing in animals and DM patients. Multistep research of the MEDLINE, PubMed, Embase, Clinicaltrials.gov, Scopus database, and Cochrane databases was conducted for abstracts and full-text scientific papers published between 2000 and 2020. Finally, 5 articles confirmed that the usage of allogeneic or autologous AD-MSCs had encouraging outcomes on diabetic wound healing. One study reported that DM changes AD-MSC function and therapeutic potential, and one article recommended that the pretreatment of diabetic allogeneic adipose-derived mesenchymal stem cells (DAlD-MSCs) was more effective in accelerating diabetic wound healing. Recently, much work has concentrated on evolving innovative healing tactics for hastening the repair of DFUs. While DM alters the intrinsic properties of AD-MSCs and impairs their function, one animal study showed that the pretreatment of DAlD-MSCs in vitro significantly increased the function of DAlD-MSCs compared with DAlD-MSCs without any treatment. Preconditioning diabetic AD-MSCs with pretreatment agents like photobiomodulation (PBM) significantly hastened healing in delayed-healing wounds. It is suggested that further animal and human studies be conducted in order to provide more documentation. Hopefully, these outcomes will help the use of DAAD-MSCs plus PBM as a routine treatment protocol for healing severe DFUs in DM patients.

Diabetic Wound-Healing Science

Diabetes mellitus is an increasingly prevalent chronic metabolic disease characterized by prolonged hyperglycemia that leads to long-term health consequences. It is estimated that impaired healing of diabetic wounds affects approximately 25% of all patients with diabetes mellitus, often resulting in lower limb amputation, with subsequent high economic and psychosocial costs. The hyperglycemic environment promotes the formation of biofilms and makes diabetic wounds difficult to treat. In this review, we present updates regarding recent advances in our understanding of the pathophysiology of diabetic wounds focusing on impaired angiogenesis, neuropathy, sub-optimal chronic inflammatory response, barrier disruption, and subsequent polymicrobial infection, followed by current and future treatment strategies designed to tackle the various pathologies associated with diabetic wounds. Given the alarming increase in the prevalence of diabetes, and subsequently diabetic wounds, it is imperative that future treatment strategies target multiple causes of impaired healing in diabetic wounds.

Impact of preconditioned diabetic stem cells and photobiomodulation on quantity and degranulation of mast cells in a delayed healing wound simulation in type one diabetic rats

Herein, we report the influence of administering different protocols of preconditioned diabetic adipose-derived mesenchymal stem cells (ADSs) with photobiomodulation in vitro, and photobiomodulation in vivo on the number of mast cells (MCs), their degranulation, and wound strength in the maturation step of a Methicillin-resistant Staphylococcus aureus (MRSA)-infectious wound model in rats with type one diabetes. An MRSA-infectious wound model was generated on diabetic animals, and they were arbitrarily assigned into five groups (G). G1 were control rats. In G2, diabetic ADS were engrafted into the wounds. In G3, diabetic ADS were engrafted into the wound, and the wound was exposed to photobiomodulation (890 nm, 890 ± 10 nm, 80 Hz, 0.2 J/cm²) in vivo. In G4, preconditioned diabetic ADS with photobiomodulation (630 and 810 nm; each 3 times with 1.2 J/cm²) in vitro were engrafted into the wound. In G5, preconditioned diabetic ADS with photobiomodulation were engrafted into the wound, and the wound was exposed to photobiomodulation in vivo. The results showed that, the maximum force in all treatment groups was remarkably greater compared to the control group (all, p = 0.000). Maximum force in G4 and G5 were superior than that other treated groups (both p = 0.000). Moreover, G3, G4, and G5 showed remarkable decreases in completely released MC granules and total numbers of MC compared to G1 and G2 (all, p = 0.000). We concluded that diabetic rats in group 5 showed significantly better results in terms of accelerated wound healing and MC count of an ischemic infected delayed healing wound model.