Background Diabetic foot ulcer is the most costly and complex challenge for patients with diabetes. We hereby assessed the effectiveness of different preconditioned adipose-derived mesenchymal stem cells (AD-MSCs) and photobiomodulation protocols on treating an infected ischemic wound in type 1 diabetic rats. Methods There were five groups of rats: (1) control, (2) control AD-MSCs [diabetic AD-MSCs were transplanted (grafted) into the wound bed], (3) AD-MSC + photobiomodulation in vivo (diabetic AD-MSCs were grafted into the wound, followed by in vivo PBM treatment), (4) AD-MSCs + photobiomodulation in vitro, and (5) AD-MSCs + photobiomodulation in vitro + in vivo. Results Diabetic AD-MSCs preconditioned with photobiomodulation had significantly risen cell function compared to diabetic AD-MSC. Groups 3 and 5 had significantly decreased microbial flora correlated to groups 1 and 2 (all, p = 0.000). Groups 2, 3, 4, and 5 had significantly improved wound closure rate (0.4, 0.4, 0.4, and 0.8, respectively) compared to group 1 (0.2). Groups 2–5 had significantly increased wound strength compared to group 1 (all p = 0.000). In most cases, group 5 had significantly better results than groups 2, 3, and 4. Conclusions Preconditioning diabetic AD-MSCs with photobiomodulation in vitro plus photobiomodulation in vivo significantly hastened healing in the diabetic rat model of an ischemic infected delayed healing wound.

The combination of bioceramics and stem cells has attracted the interest of research community for bone tissue engineering applications. In the present study, a combination of Bio-Oss(®) and type 1 collagen gel as scaffold were loaded with human adipose-tissue derived mesenchymal stem cells (AT-MSCs) after isolation and characterization, and the capacity of them for bone regeneration was investigated in rat critical size defects using digital mammography, multi-slice spiral computed tomography imaging and histological analysis. 8 weeks after implantation, no mortality or sign of inflammation was observed in the site of defect. According to the results of imaging analysis, a higher level of bone regeneration was observed in the rats receiving Bio-Oss(®)-Gel compared to untreated group. In addition, MSC-seeded Bio-Oss-Gel induced the highest bone reconstruction among all groups. Histological staining confirmed these findings and impressive osseointegration was observed in MSC-seeded Bio-Oss-Gel compared with Bio-Oss-Gel. On the whole, it was demonstrated that combination of AT-MSCs, Bio-Oss and Gel synergistically enhanced bone regeneration and reconstruction and also could serve as an appropriate structure to bone regenerative medicine and tissue engineering application.

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Introduction: Many studies have shown the positive effect of laser radiation and application of the mesenchymal stem cells (MSCs) and their secretion in stimulating bone regeneration. The aim of this study was determining effects of MSC conditioned media (CM) and low-level laser (LLL) on healing bone defects in the hypothyroid male rat. Methods: We assigned 30 male Wistar rats randomly to 3 groups: control, hypothyroidism, CM+LLL. Four weeks after surgery, the right tibia was removed. Biomechanical examination and histological examinations were performed immediately. Results: Our results showed significant increase in bending stiffness (116.09±18.49), maximum force (65.41±8.16), stress high load (23.30±7.14), energy absorption (34.57±4.10), trabecular bone volume (1.34±0.38) and the number of osteocyte, osteoblast, and osteoclast (12.77±0.54, 6.19±0.80, 1.12±0.16 respectively) in osteotomy site in the LLL+CM group compared to the hypothyroidism group (P<0.05). Conclusion: The results indicated that using the LLL + CM may improve fracture regeneration and it may hasten bone healing in the hypothyroid rat.

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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.

The spatial arrangement of the cell is important and considered as underlying mechanism for mathematical modeling of cell to cell interaction. The ability of cells to take on the characteristics of other cells in an organism, it is important to understand the dynamical behavior of the cells. This method implements experimental parameters of the cell-cell interaction into the mathematical simulation of cell arrangement. The purpose of this research was to explore the three-dimensional spatial distribution of anterior horn cells in the rat spinal cord to examine differences after sciatic nerve injury. Sixteen Sprague-Dawley male rats were assigned to control and axotomy groups. Twelve weeks after surgery, the anterior horn was removed for first- and second-order stereological studies. Second-order stereological techniques were applied to estimate the pair correlation and cross-correlation functions using a dipole probe superimposed onto the spinal cord sections. The findings revealed 7% and 36% reductions in the mean volume and total number of motoneurons, respectively, and a 25% increase in the neuroglial cell number in the axotomized rats compared to the control rats. In contrast, the anterior horn volume remained unchanged. The results also indicated a broader gap in the pair correlation curve for the motoneurons and neuroglial cells in the axotomized rats compared to the control rats. This finding shows a negative correlation for the distribution of motoneurons and neuroglial cells in the axotomized rats. The cross-correlation curve shows a negative correlation between the motoneurons and neuroglial cells in the axotomized rats. These findings suggest that cellular structural and functional changes after sciatic nerve injury lead to the alterations in the spatial arrangement of motoneurons and neuroglial cells, finally affecting the normal function of the central nervous system. The experimental protocol was reviewed and approved by the Animal Ethics Committee of Shahid Beheshti University of Medical Sciences (approval No. IR.SBMU.MSP.REC1395.375) on October 17, 2016.

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