Back Of Wistar Rats Research Articles

A Novel Model of Perifascial Areolar Tissue Transplant in Rats.

Background Perifascial areolar tissue (PAT) transplant is a method of transplanting loose connective tissue harvested in a sheet form from above the fascia to the wound bed and is effective for wounds with exposed ischemic tissue. However, the engraftment mechanism is unknown, and no animal models of PAT transplant for wound healing exist. Methods In this study, we harvested connective tissue from the backs of Wistar rats in a sheet form to simulate a human PAT transplant. The PAT was affixed to exposed bone of the head. Results In the PAT(+) group, the wound areas gradually decreased due to epithelialization and contraction. The wound area of the PAT(+) group was significantly smaller than that of the PAT(-) group. Conclusions This clinically relevant rat model is useful for elucidating the mechanism of the PAT transplant and establishing a reliable surgical method.

PMMA nanofibers containing Keplerate-type polyoxometalate and metronidazole: Preparation and wound-healing effect in a rat model

Wound healing is crucial because it entails a complex cellular process that complicates the design of scaffolds for therapeutic purposes. Present study is focused on the development of a new wound dressing based on polymethyl methacrylate nanofibers containing Mo72Fe30 as a Keplerate-type polyoxometalate with efficient and controlled delivery of metronidazole during wound healing. The hydrophilic nature of biocompatible Mo72Fe30 along with the antibiotic and wound healing properties of metronidazole were utilized to develop an efficient wound dressing. The efficient and controlled release of metronidazole was assisted by the presence of Keplerete as an anion and metronidazole as a cation. The nanofibers were prepared by electrospinning of appropriate solution and characterized by FT-IR, XRD, FE-SEM, EDX, TGA, and elemental analysis. The surface wettability, microstructure, water absorption capacity, mechanical properties, in-vitro biocompatibility, drug release behavior, and in-vivo wound healing of prepared dressings were also evaluated. The in-vivo animal studies (injury created on the back of Wistar rats) showed the complete healing of wounds after 14 days of being covered by wound dressing compared to a sterile gauze, which shows approximately 45% reduction in wound size. The amounts of wound closure using dressing were found to be 95.26 and 97.97% after 7 and 14 days of wounding, respectively. The overall results indicated the high potential of these nanofiber-based dressings for wound healing.

Local and Remote Effects of Mesenchymal Stem Cell Administration on Skin Wound Regeneration.

Wound healing is an important medical problem. We evaluated the efficacy of locally administered mesenchymal stem cells (MSCs) isolated from human umbilical cords on the dynamics of skin wound healing. The study was conducted on the backs of Wistar rats, where two square wounds were created by removing all layers of the skin. Four groups were studied in two series of experiments: (1) a Control_NaCl group (the wounds were injected with 0.9% NaCl solution) and a Control_0 group (intact wounds on the opposite side of the same rat’s back); (2) an MSC group (injected MSCs, local effect) and a Control_sc group (intact wounds on the opposite side of the back, remote MSC effect). The area and temperature of the wounds and the microcirculation of the wound edges were measured. Histological and morphometric studies were performed on days 3 and 7 after the wounds were created. The results showed that the injection trauma (Control_NaCl) slowed the regeneration process. In both MSC groups (unlike in either control group), we observed no increase in the area of the wounds; in addition, we observed inhibition of the inflammatory process and improved wound regeneration on days 1–3 in the remote group and days 1–5 in the local (injected) group. The MSC and Control_sc groups demonstrated improved microcirculation and suppression of leukocyte infiltration on day 3. On day 7, all the studied parameters of the wounds of the Control_0 group were the same as those of the wounds that received cell therapy, although in contrast to the results of the Control_ NaCl group, fibroblast proliferation was greater in the MSC and Control_sc groups. The dynamics of the size of the wounds were comparable for both local and remote application of MSCs. Thus, even a one-time application of MSCs was effective during the first 3–5 days after injury due to anti-inflammatory processes, which improved the regeneration process. Remote application of MSC, as opposed to direct injection, is advisable, especially in the case of multiple wounds, since the results were indistinguishable between the groups and injection trauma was shown to slow healing.

Comparative Analysis of Connective Tissue Responses to Implantation of Biodegradable Material and Polypropylene in Experimental Animals.

We compared qualitative characteristics of the connective tissue at the site of implantation of polypropylene or a biodegradable polymer synthesized by electrospinning and consisting of 65% polycaprolactone and 35% polytrimethylene carbonate. Synthetic materials were implanted into the interfascial space of the muscles on the back of Wistar rats. The parameters of cellular and non-cellular structures of the forming connective tissue were studied in 1, 2, 3, 6, 9, and 12 months after implantation. It was found that the number of fibrocytes and fibroblasts around biopolymer and polypropylene increased during the period from 1 to 9 months, with a significant lag in case of biopolymer implantation; by 12 months, the number of fibrocytic cells did not significantly differ. The fibroplastic and angioplastic processes developed in the thickness of both materials, but with a one-month lag in case of biopolymer implantation due to degradation properties and nonporous structure of this polymer. Collagen fibers were actively synthesized around both materials, but in case of polypropylene, this process was more pronounced. In 6 months after implantation of polypropylene, dense regular connective tissue was formed; in 12 months after implantation of the biopolymer, the formation of dense irregular connective tissue was observed at the site of implantation. The biopolymer can be used to strengthen the core muscles.

Kinesio Taping decreases healing area and modulates the tissue architecture on the cutaneous wound

The skin is an organ that promotes elasticity and also resistance against mechanical forces. After injury, its organization is altered by the repair process, compromising the physiological mechanical conditions of the skin. In this context, it has been demonstrated that Kinesio Taping (KT) accelerates the cicatricial process and prevents the development of skin adhesions, but other actions of this method in the cutaneous repair tissue remain indeterminate. Objective: To investigate the histological effects of KT in tissue repair of cutaneous wound. Methods: The procedure involved the preparation and suturing of an incisional wound of 5 cm in length on the epilated back of Wistar rats. After ten days, KT was applied with different stretch levels - 0, 20, 40, 60, 80 and 100% - for six hours. The skin fragment corresponding to the scar was collected and analysed by histological procedures. Results: KT decreased repair tissue area, regardless of the degree of strain, while mast cells activity was not affected by the treatment. 80% stretched KT increased the vascular density of repair tissue. Also, there was a predominance of type III collagen fibers over type I in all groups treated with KT and modulation in tissue architecture in GKT100.

Evaluation of Wound Healing Activity of an Ethanolic Extract of Anacardiumoccidentale Leaves in Wistar Rats

BACKGROUND -This study undertaken to screen a potential wound healing activity of an ethanolic extract of Anacardiumoccidentale(Ao)leaves in Wistar rats. MATERIALS AND METHODS-Excision wound of 500mm2created on the back of Wistar rats. A total of thirty adult Wistar rats were prescreened and divided into five groups of six rats each.Group I and II rats were treated by normal saline (control) and povidone-iodine (standard drug), respectively. Group III and IV with 0.5% and 2%of Anacardiumoccidentale ointment (test drugs), respectively, and Group V rats treated with anti-wound healer drug dexamethasone, i.m. + 2% Anacardiumoccidentale. All drugs were applied topically except Inj. dexamethasone. In the model of excision wound, the wound healing effect was determined by parameters such as the percentage of wound contraction, duration of epithelialization, and histopathological examination. RESULT-All drugs, povidone-iodine, 0.5%, and 2% of the Ao ointment treated group of rats showed a statistically significant increase (P<0.05) in the % of wound contraction on 5th and 6thdays Vs.Control rats. In contrast,povidone-iodine, 2% Ao ointment and (dexamethasone + 2% Ao)treated rats decreased the period of epithelialization which was statistically significant (P<0.05) compared to the control.However, the standard povidone-iodine treated rats showed a maximum increase in the percentage of wound contraction and minimum period of epithelialization, followed by a higher dose of 2% Ao extract. The plant extract 0.5% and 2% of Ao showeda significant increase inthe rate of wound contraction as compared to the standard drug povidone-iodine also. The combination of (2%Aoextract+dexamethasone) drug-treated rats decreased the rate of wound contraction on 5th, 9th days; whereas, povidone-iodine increased on all days, i.e., 5th, 9th, 13th and 17th days,which was statistically significant (p<0.05) Vs.Normal saline. The povidone and 2% of Ao extract hastened the rate of wound healing activity, which was evident by maximum re-epithelialization and presence of the collagen fibers. CONCLUSION-In our study, the topical application of Anacardiumoccidentale leaf extract has shown promising wound healing activity; however, it failed to reverse the anti-wound healing property of steroids.

Synthesis and characterization of ester-diol based polyurethane: a potentiality check for hypopharyngeal tissue engineering application.

Hypopharyngeal tissue engineering is increasing rapidly in this developing world. Tissue damage or loss needs the replacement by another biological or synthesized membrane using tissue engineering. Tissue engineering research is emerging to provide an effective solution for damaged tissue replacement. Polyurethane in tissue engineering has successfully been used to repair and restore the function of damaged tissues. In this context, Can polyurethane be a useful material to deal with hypopharyngeal tissue defects? To explore this, here ester diol based polyurethane (PU) was synthesized in two steps: firstly, polyethylene glycol 400 (PEG 400) was reacted with lactic acid to prepare ester diol, and then it was polymerized with hexamethylene diisocyanate. The physical, mechanical, and biological testing was done to testify the characterization of the membrane. The morphology of the synthesized membrane was investigated by using field emission scanning electron microscopy. Functional groups of the obtained membrane were characterized by fourier transform infrared spectroscopy spectroscopy. Several tests were performed to check the in vitro and in vivo biocompatibility of the membrane. A highly connected homogeneous network was obtained due to the appropriate orientation of a hard segment and soft segment in the synthesized membrane. Mechanical property analysis indicates the membrane has a strength of 5.15MPa and strain 124%. The membrane showed high hemocompatibility, no cytotoxicity on peripheral blood mononuclear cell, and susceptible to degradation in simulated body fluid solution. Antimicrobial activity assessment has shown promising results against clinically significant bacteria. Primary hypopharyngeal cell growth on the PU membrane revealed the cytocompatibility and subcutaneous implantation on the back of Wistar rats were given in vivo biocompatibility of the membrane. Therefore, the synthesized material can be considered as a potential candidate for a hypopharyngeal tissue engineering application.

Bioactivity and biomineralization ability of calcium silicate-based pulp-capping materials after subcutaneous implantation.

To evaluate the abilities of three calcium silicate-based pulp-capping materials (ProRoot MTA, TheraCal LC and a prototype tricalcium silicate cement) to produce apatite-like precipitates after being subcutaneously implanted into rats. Polytetrafluoroethylene tubes containing each material were subcutaneously implanted into the backs of Wistar rats. At 7, 14 and 28days post-implantation, the implants were removed together with the surrounding connective tissue, and fixed in 2.5% glutaraldehyde in cacodylate buffer. The chemical compositions of the surface precipitates formed on the implants were analysed with scanning electron microscopy-electron probe microanalysis (SEM-EPMA). The distributions of calcium (Ca) and phosphorus (P) at the material-tissue interface were also analysed with SEM-EPMA. Comparisons of the thicknesses of the Ca- and P-rich areas were performed using the Friedman test followed by Scheffe's test at a significant level of 5%. All three materials produced apatite-like surface precipitates containing Ca and P. For each material, elemental mapping detected a region of connective tissue in which the concentrations of Ca and P were higher than those in the surrounding connective tissue. The thickness of this Ca- and P-rich region exhibited the following pattern: ProRoot MTA > prototype tricalcium silicate cement≥TheraCal LC. ProRoot MTA had a significantly thicker layer of Ca and P than the other materials at all time-points (P<0.05), and a significant difference was detected between the prototype cement and TheraCal LC at 28days (P<0.05). After being subcutaneously implanted, all of the materials produced Ca- and P-containing surface precipitates and a Ca- and P-rich layer within the surrounding tissue. The thickness of the Ca- and P-rich layer of ProRoot MTA was significantly thicker than that of the other materials.

3,4-Methylenedioxy-β-Nitrostyrene Ameliorates Experimental Burn Wound Progression by Inhibiting the NLRP3 Inflammasome Activation.

Burn wound progression remains a challenging problem in the clinic. Secondary tissue damage caused by unlimited inflammatory response is considered to be one of the key factors contributing to this clinical problem. Nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome has recently been found to play important roles in immune activation and the inflammatory response after burn/trauma. This experimental study aims (1) to observe the expression and distribution of NLRP3 inflammasome in burn wounds of a rat burn model and (2) to study whether inhibiting the NLRP3 inflammasome activation would ameliorate burn wound progression. A deep second-degree burn was inflicted on the backs of Wistar rats. The expression of NLRP3 inflammasome components and interleukin-1β were determined by Western blot and coimmunoprecipitation. The distribution of NLRP3 inflammasome was assessed by immunohistochemical staining and double-labeling immunofluorescence. Neutrophil infiltration, wound perfusion, burn depth, and wound healing time were assessed. Burn induced remarkable NLRP3 inflammasome activation and cleavage of interleukin-1β. The NLRP3 inflammasome was observed mainly in macrophages of the zone of stasis. 3,4-Methylenedioxy-β-nitrostyrene significantly inhibited NLRP3 inflammasome activation and inflammatory cytokine production in burn wounds. Consequently, neutrophil infiltration was reduced, wound perfusion was restored, burn wound progression was ameliorated, and wound healing was accelerated. In this study, the authors demonstrated that burn induced NLRP3 inflammasome activation and inflammatory response in wounds, which may be associated with burn wound progression. Treatment with 3,4-methylenedioxy-β-nitrostyrene inhibited NLRP3 inflammasome activation, ameliorated burn wound progression, and promoted wound healing.

Interaction between Macrophages and Fibroblasts during Wound Healing of Burn Injuries in Rats.

Analysis of the structural changes and cell-to-cell interactions occurring during wound healing of burn injuries is essential to elucidate the morphological characteristics of the reconstitution of tissue architecture. However, conventional approaches do not provide sufficient information with respect to cell-to-cell interactions during wound healing. The aim of this study was to evaluate the interaction between bone marrow-derived cells and resident stromal cells throughout the wound healing of burn injuries, using immunohistochemistry and focused ion beam/scanning electron microscope tomography. We induced third-degree burn injuries on the backs of Wistar rats with a heated cylindrical aluminum block (2.0 cm in diameter). At 7 and 14 days after the burn injuries, the burned skin was immunostained with anti-Iba1 and anti-HSP47 antibodies for visualization of bone marrow-derived cells/macrophages and resident stromal cells/fibroblasts, respectively. Normal skin tissue was used as a control. Double-staining immunohistochemistry revealed frequent contacts between macrophages and fibroblasts and a higher contact ratio in the 3 normal skin compared with burned skin, particularly in the areas of granuloma. Three-dimensional ultrastructural analysis with focused ion beam/scanning electron microscope tomography revealed that macrophages and fibroblasts were located closer together in the normal skin than in the burned skin, confirming the analysis by light microscopic observations and ultrastructural analysis from single sections. These results highlight the importance of contact between macrophages and fibroblasts in the maintenance of skin tissue structure and during wound healing.

Application of 670 nm InGaP laser and microcurrent favors the healing of second-degree burns in Wistar rats

The treatment of burn wounds has been a challenge due to their severity and associated multiple complications, and represents a major public health problem. This study investigated the effects of 670 nm InGaP laser irradiation and microcurrent (10 µA) stimulation on the healing of second-degree burns inflicted on the back of Wistar rats. Seventy-two animals were divided into four groups: no treatment (C); animals irradiated with a 670 nm InGaP laser (L); animals receiving microcurrent stimulation (10 µA/3 min) (MC); animals receiving 670 nm InGaP laser therapy and microcurrent stimulation (10 µA/3 min) on alternate days (MCL). Wound samples were collected on days 7, 14 and 21 of treatment for structural and morphometric analysis and for Western blotting to quantify the expression of TGF-β1 and VEGF. The applied alone and alternate of laser and microcurrent reduced the number of inflammatory cells and increased the number of newly formed vessels and fibroblasts, collagen fiber content and fiber reorganization. The two treatments also favorably modified the expression of VEGF and TGF-β1, inducing angiogenesis and decreasing the inflammation time.

Effects of laser irradiation (670-nm InGaP and 830-nm GaAlAs) on burn of second-degree in rats

This study investigated the effects of 670-nm indium gallium phosphide (InGaP) and 830-nm gallium aluminum arsenide (GaAlAs) laser therapy on second-degree burns induced on the back of Wistar rats. Sixty-three male Wistar rats were anesthetized, and second-degree burns were made on their back. The animals were then divided randomly into three groups: control (C), animals treated with 670-nm InGaP laser (LIn), and animals treated with 830-nm GaAlAs laser (LGa). The wound areas were removed after 2, 6, 10, 14, and 18 days of treatment and submitted to structural and morphometric analysis. The following parameters were studied: total number of granulocytes and fibroblasts, number of newly formed blood vessels, and percentage of birefringent collagen fibers in the repair area. Morphometric analysis showed that different lasers 670-nm InGaP and 830-nm GaAlAs reduced the number of granulocytes and an increase of newly formed vessels in radiated lesions. The 670-nm InGaP laser therapy was more effective in increasing the number of fibroblasts. The different treatments modified the expression of VEGF and TGF-β1, when compared with lesions not irradiated. The different types of light sources showed similar effects, improved the healing of second-degree burns and can help for treating this type of injury. Despite the large number of studies with LLTI application in second-degree burns, there is still divergence about the best irradiation parameters to be used. Further studies are needed for developing a protocol effective in treating this type of injury.

In vivo Evaluation of Hair Growth Potential of Fresh Leaf Extracts of Naringi Crenulata

Hair growth problems can affect human physical and mental health and are of particular relevance during the aging process. In an effort to resolve such problems, an attempt has been made to evaluate the hair growth promotion activity of fresh leaf extracts of Naringi crenulata by using rodent model. Crude extracts of 0.2 ml were applied over the shaved skin onto the backs of wistar rats and monitored for 30 days. After 30 days, rats were treated with acetone and Chloroform produced a greater effect on the length and weight of hair, number of hair follicles, blood circulation and colouration of shaved skin as compared to the control groups. Therefore the results of this study suggest that, Naringi crenulata has hair growth promoting potential, the effect of which may be attributed to the presence of terpenoids and flavonoids in the plant extracts.

Effects of minoxidil gel on burn wound healing in rats.

Minoxidil has been reported to inhibit in-vitro fibroblast proliferation and lysyl hydroxylase activity, a key enzyme in collagen biosynthesis. These in-vitro effects proposed minoxidil to be a potential antifibrotic agent. The present study aimed to investigate the effects of minoxidil gel on wound healing procedure in a second-degree burn model in rats. Wistar rats were anesthetized and a second-degree burn was induced on the back of Wistar rats using a heated 2 cm diameter metal plate. Experimental groups received 2% or 5% topical minoxidil gel, dexpanthenol or sliver sulfadiazine. Histological parameters including collagen content, angiogenesis, number of preserved follicles and necrosis along with tensile strength of burn wound area were assessed on days 3, 7, 14 and 21 post-injury.Microscopic evaluation of specimens collected from sample animals were consistent and showed a second-degree burn. Main histological findings regarding minoxidil topical usage showed that collagen content and tensile strength of burned area did not differ between groups. However, minoxidil increased the number and diameter of blood vessels significantly compared with other groups.Although minoxidil improved the process of wound-healing, our results did not support the proposed idea of its usage as an antifibrotic agent. However, to reject its possible effects as an antifibrotic agent, more objective animal models should be developed and studied.

M2 Macrophages Participate in the Biological Tissue Healing Reaction to Mineral Trioxide Aggregate

IntroductionThis study examined the protein and messenger RNA (mRNA) expression of molecules associated with M2 (wound healing) macrophages in mineral trioxide aggregate (MTA)-implanted rat subcutaneous tissue to elucidate the involvement of M2 macrophages in the connective tissue response to MTA. MethodsSilicone tubes containing freshly mixed MTA or a calcium hydroxide cement (Life; Kerr, Romulus, MI) were subcutaneously implanted into the backs of Wistar rats. Solid silicone rods implanted in different animals served as controls. The specimens were then double immunostained for ED1 (CD68, a general macrophage marker) and ED2 (CD163, an M2 macrophage marker). Immunostaining for CD34 (a marker for vascularization and wound healing) was also performed. Expression levels of CD34, CD163, and mannose receptor c type 1 (an M2 macrophage marker) mRNAs were determined with real-time polymerase chain reaction. ResultsMTA-implanted subcutaneous tissues showed significant increases in the density of ED1+ED2+ macrophages beneath the implantation site and expression levels of CD163 and MMR mRNAs compared with Life-implanted and control tissues. MTA-implanted subcutaneous tissues also showed a significant increase of CD34-immunostained areas and up-regulation of CD34 mRNAs compared with Life-implanted and control tissues. ConclusionsMTA implantation induced the accumulation of M2 macrophage marker (ED2)-expressing macrophages and enhanced the expression of M2 macrophage marker genes. MTA implantation also enhanced the expression of CD34, suggesting acceleration of the healing/tissue repair process. Taken together, biological connective tissue response to MTA may involve wound healing/tissue repair processes involving M2 macrophages.

The influence of zi-hua burn cream on the survival of random skin flaps in rats

To observe the effect of zi-hua burn cream on the survival of skin flaps in rats, and its mechanisms. 72 Wistar rats, were randomly divided into four groups as zi-hua group(n = 18, external application of alfalfa burn cream), control group (n = 18, external application of heparin sodium cream), model group (n = 18, external application of vaseline) , negative control (n = 18, no operation). 8 cm x 2 cm random skin flaps with pedicle on the side of head were designed on the back of Wistar rats. The drug was applied on the flap surface, 2 times a day. The survival of skin flaps was observed. The change of serum superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), turner necrosis factor-alpha(TNF-alpha)and interleukin-6(IL-6)were compared at 1,2,3,7 d after operation, and histologic examination was performed. The survival rate of zi-hua group (73.58 - 10. 74)% was significantly higher than that of model group (33.40 - 16.05) %, showing a statistical difference (Q = 10.63, P <0.01). There was no significant difference between the zi-hua group and control group (71.65 +/- 11. 92) %. The level of serum SOD, NO in zi-hua group and control group was higher than that in model group, while the level of serum MDA, TNF-alpha and IL-6 was lower than that in model group(P <0.01). On 7 day after operation, skin flaps tissue edema,necrosis and inflammatory cell infiltration in zi-hua group and control group was less obvious than that in model group. There was significant proliferation of granuloma and fibroblast and formation of neonatal capillary in zi-hua group and control group. The vascular density in zi-hua group was obviously higher than that in the model group and control group(P <0. 01). Zi-hua burn cream could significantly improve the blood supply of skin flaps, increase the survival rate of skin flaps in rats. Its mechanism may be associated with the anti-free-radical-damage action, improve local microcirculation, improve the NO content, reduce the TNF-alpha and IL-6 level, reduce inflammation factor release, improve oxidative stress state, and reduce inflammation reaction.

Healing potential of aStreptomycessp. secondary metabolite, SEM-1-111, on experimental full-thickness excision cutaneous wounds in Wistar rats

The potent biomedical properties of Streptomyces secondary metabolites make them a possible source of promising new targets to use as wound-healing-promoting agents. To investigate the properties of a Streptomyces sp. secondary metabolite, the SEM-1-111 fraction, in the healing full-thickness cutaneous wounds. In this experiment, creams were prepared using a Eucerin ointment base with 5%, 10% or 15% SEM-1-111 added. Circular excision wounds were surgically created on the back of Wistar rats, and the creams were applied daily to the wound area. The negative control group was treated with the vehicle, and the positive control group with a commercial phenytoin 1% cream. We analysed planimetric and histological parameters, and the expression of procollagen-I mRNA. SEM-1-111 substantially influenced wound healing. The cream containing the highest dose of metabolite (15%) significantly decreased wound size during the study, and histological evaluation showed beneficial effects of this concentration in the wound-healing process. Procollagen-I mRNA levels were significantly increased in both the 15% SEM-1-111 group and the phenytoin group compared with the vehicle control on postoperative day 7. Regular topical application of the Streptomyces sp. secondary metabolite SEM-1-111 fraction at a concentration of 15% accelerates the wound-healing process.

The Use of Injectable Chitosan/Nanohydroxyapatite/Collagen Composites with Bone Marrow Mesenchymal Stem Cells to Promote Ectopic Bone Formation In Vivo

The aim of this study was to evaluate ectopic in vivo bone formation with or without rat bone mesenchymal stem cells (rBMSCs) of an injectable Chitosan/Nanohydroxyapatite/Collagen (CS/nHAC) composite. The CS/nHAC composites were injected subcutaneously into the backs of Wistar rats with freshly loaded rBMSCs at a density of 10 × 106 cells/mL, and the CS/nHAC composites without cells were used as negative controls. New bone formation, degradation of composites, and degree of calcification were evaluated by Computed Tomography (CT) and three‐dimensional (3D) CT reconstruction. Histological evaluations were performed to further assess bone structure and extracellular matrix by HE and Masson staining. The inflammatory reactions related to osteogenesis were also investigated in the present study. In comparison with the CS/nHAC composites, this study revealed that CS/nHAC/rBMSCs composites showed relatively higher percentage of calcification, better establishment of ECM, and less degradation rate. Meanwhile, different extents of inflammatory reactions were also observed in the CS/nHAC and CS/nHAC/rBMSCs explants at 2 and 4 weeks after implantation. Altogether, CS/nHAC/rBMSCs composites are superior to CS/nHAC composites in ectopic bone formation. In conclusion, the rBMSCs‐seeded CS/nHAC composites may be beneficial to enhancing ectopic bone formation in vivo.

In vivo wound healing and antiulcer properties of white sweet potato (Ipomoea batatas)

The potential of tuber flour of Ipomoea batatas (L.) Lam. cv. Brazlândia Branca (white sweet potato) as wound healing and antiulcerogenic agent was investigated in vivo in animal model. Excision on the back of Wistar rats was performed to induce wounds that were topically treated with Beeler’s base containing tuber flour of white sweet potato at 2.5%. Number of cells undergoing metaphase and the degree of tissue re-epithelialization were investigated 4, 7 and 10days post-treatment. The protective effect of aqueous suspension of tuber flour (75 and 100mg/kg animal weight) on gastric mucosa of Wistar rats was also studied by using the ethanol-induced ulceration model. Ointment based on white sweet potato at 2.5% effectively triggered the healing of cutaneous wound as attested by the increased number of cells undergoing metaphase and tissue re-epithelialization regardless the time of wound treatment. Tuber flour potentially prevented ethanol-induced gastric ulceration by suppressing edema formation and partly protecting gastric mucosa wrinkles. Crude extracts also exhibited potential as free radical scavengers. The results from animal model experiments indicate the potential of tuber flour of white sweet potato to heal wounds.

Effects of microcurrent application alone or in combination with topical Hypericum perforatum L. and Arnica montana L. on surgically induced wound healing in Wistar rats

This study evaluated the wound healing activity of microcurrent application alone or in combination with topical Hypericum perforatum L. and Arnica montana L. on skin surgical incision surgically induced on the back of Wistar rats. The animals were randomly divided into six groups: (1) no intervention (control group); (2) microcurrent application (10 μA/2 min); (3) topical application of gel containing H. perforatum; (4) topical application of H. perforatum gel and microcurrent (10 μA/2 min); (5) topical application of gel containing A. montana; (6) topical application of A. montana gel and microcurrent (10 μA/2 min). Tissue samples were obtained on the 2nd, 6th and 10th days after injury and submitted to structural and morphometric analysis. Differences in wound healing were observed between treatments when compared to the control group. Microcurrent application alone or combined with H. perforatum gel or A. montana gel exerted significant effects on wound healing in this experimental model in all of the study parameters (P<0.05) when compared to the control group with positive effects seen regarding newly formed tissue, number of newly formed blood vessels and percentage of mature collagen fibers. The morphometric data confirmed the structural findings. In conclusion, application of H. perforatum or A. montana was effective on experimental wound healing when compared to control, but significant differences in the parameters studied were only observed when these treatments were combined with microcurrent application.