Analysis of Mechanical Behavior of Dermal Fibroblasts Obtained From Various Anatomical Sites in Humans.

PURPOSE: Facial skin fibroblasts imposed with cyclic stretch at 10% magnitude display considerable mechanotransduction properties and biochemical reactions in our previous study. However, it is poorly understood how these shared traits are fully parallel to the common features across all fibroblasts derived from different skin-based anatomical regions in response to cyclic stretch stimulation. Thus, the purpose of this study was to evaluate the effects of various cyclic stretches on fibroblasts derived from multiple anatomical skin sites of human bodies, and the optimal stretch magnitude was defined based on the changes to cell mechanical behavior. METHODS: Fibroblasts from skin areas of the scalp, anterior chest, suprapubic, axilla, and planta were cultured and characterized in vitro. Cyclic stretch at 0%, 5%, 10%, 15%, and 20% magnitudes was imposed at a loading frequency of 0.1 Hz for 48 hours, and thereafter, the mechanical behavior and biochemical reaction of the dermal fibroblasts were analyzed. RESULTS: Dermal fibroblasts from various anatomical sites preconditioned with varying cyclic stretch led to an evident increase in the cell proliferation ability, the expression of integrin ß1 and p130 Crk-associated substrate messenger RNA and protein, and the productions of type I collagen and transforming growth factor ß1, most importantly in a strain magnitude-dependent manner with the peak appearing in the range of 10% to 15% magnitude cyclic stretch. CONCLUSIONS: These findings may facilitate the subsequent studies on the conversion of normal skin fibroblasts into hypertrophic scar cells, which should be considered in an interpretation of the mechanisms of hypertrophic scarring and skin mechanics.

Irisin attenuates vascular remodeling in hypertensive mice induced by Ang II by suppressing Ca2+-dependent endoplasmic reticulum stress in VSMCs.

Vascular remodeling plays a vital role in hypertensive diseases and is an important target for hypertension treatment. Irisin, a newly discovered myokine and adipokine, has been found to have beneficial effects on various cardiovascular diseases. However, the pharmacological effect of irisin in antagonizing hypertension-induced vascular remodeling is not well understood. In the present study, we investigated the protection and mechanisms of irisin against hypertension and vascular remodeling induced by angiotensin II (Ang II). Adult male mice of wild-type, FNDC5 (irisin-precursor) knockout, and FNDC5 overexpression were used to develop hypertension by challenging them with Ang II subcutaneously in the back using a microosmotic pump for 4 weeks. Similar to the attenuation of irisin on Ang II-induced VSMCs remodeling, endogenous FNDC5 ablation exacerbated, and exogenous FNDC5 overexpression alleviated Ang II-induced hypertension and vascular remodeling. Aortic RNA sequencing showed that irisin deficiency exacerbated intracellular calcium imbalance and increased vasoconstriction, which was parallel to the deterioration in both ER calcium dysmetabolism and ER stress. FNDC5 overexpression/exogenous irisin supplementation protected VSMCs from Ang II-induced remodeling by improving endoplasmic reticulum (ER) homeostasis. This improvement includes inhibiting Ca2+ release from the ER and promoting the re-absorption of Ca2+ into the ER, thus relieving Ca2+-dependent ER stress. Furthermore, irisin was confirmed to bind to its receptors, αV/ß5 integrins, to further activate the AMPK pathway and inhibit the p38 pathway, leading to vasoprotection in Ang II-insulted VSMCs. These results indicate that irisin protects against hypertension and vascular remodeling in Ang II-challenged mice by restoring calcium homeostasis and attenuating ER stress in VSMCs via activating AMPK and suppressing p38 signaling.

[Application principles of hatchet skin flap for repairing tissue defect of cheek].

OBJECTIVE: To evaluate the design principles, clinical results and significance of hatchet skin flaps for repairing tissue defects in different parts of cheek. METHODS: The area of cheek was divided into three parts, P(I), P(II) and P(III), with vertical lines through the medial canthus and lateral canthus. Different kinds of hatchet skin flaps were designed to repair tissue defects in different part of cheek. The hatchet skin flaps were performed in 29 cases with tissue defects in different part of cheek from August 2005 to August 2009. There were 17 male and 12 female, aged from 19 to 81 years, with a mean age of (45 ± 16) years. The size of tissue defect ranged from 1.5 cm × 1.5 cm to 2.5 cm × 3.5 cm. Patients' satisfactions were evaluated with a questionnaire in 5 aspects:color and texture match, scar, morbidity, and function after 6 months operatively. RESULTS: All the flaps survived completely with good color and tissue match. The facial contour was not altered obviously. Six to eighteen months later, all scars were almost invisible. All 29 patients were satisfied with their results. CONCLUSIONS: The hatchet skin flap is one of the versatile reconstructive methods for repairing of medium and small defects in the three parts of cheek. Defects in different part of cheek should be repaired individually with hatchet flap based on characters of natural lines.

Systemic BMSC homing in the regeneration of pulp-like tissue and the enhancing effect of stromal cell-derived factor-1 on BMSC homing.

Pulp regeneration caused by endogenous cells homing has become the new research spot in endodontics. However, the source of functional cells that are involved in and contributed to the reconstituting process has not been identified. In this study, the possible role of systemical BMSC in pulp regeneration and the effect of stromal cell-derived factor-1 (SDF-1) on stem cell recruitment and angiogenesis were evaluated. 54 mice were divided into three groups: SDF-1 group (subcutaneous pockets containing roots with SDF-1 absorbed neutralized collagen gel and the green fluorescent protein (GFP) positive BMSCs transplantation via the tail vein), SDF-1-free group (pockets containing roots with gel alone and GFP + BMSCs transplantation) and Control group (pockets containing roots with gel alone). The animals were sacrificed after the roots were implanted into subcutaneous pockets for 3 weeks. Histomorphometric analysis was performed to evaluate the regenerated tissue in the canal by hematoxylin and eosin (HE) staining. The homing of the transplanted BMSCs was monitored with a fluorescence microscope and immunohistochemical analysis. The expression of ALP in new formed tissue was detected immunohistochemically. Dental-pulp-like tissue and new vessels were regenerated and GFP-positive BMSCs and expression of ALP could be observed in both SDF-1 group and SDF-1-free group. Furthermore, more GFP+ cells, stronger expression of ALP and stronger angiogenesis were found in the SDF-1 group than in the SDF-1-free group. To conclude, systemic BMSC can home to the root canal and participate in dental-pulp-like tissue regeneration. Intracanal application of SDF-1 may enhance BMSC homing efficiency and angiogenesis.

Hyperlipidemia compromises homing efficiency of systemically transplanted BMSCs and inhibits bone regeneration.

PURPOSE: Mesenchymal stem cells (MSCs) can selectively home to bone defects and play an essential role in promoting bone regeneration. As an adverse effect factor for bone metabolism, hyperlipidemia significantly impairs bone regeneration. In this study, bone marrow stromal cells (BMSCs) were systemically transplanted into a hyperlipidemic mouse model to explore the effect of hyperlipidemia on stem cell recruitment and bone regeneration. METHODS: Hyperlipidemia was established in ApoE-/- mice (on C57BL/6J background) fed with a high fat diet (HFD) for five weeks. C57BL/6 mice fed with the same diet served as controls. BMSCs labeled with the green fluorescent protein (GFP) were then injected via the tail vein and bone defects were created in the mandibles. The animals were sacrificed at weeks 1, 2 and 4 after surgery, and the fate of the transplanted BMSCs was monitored with a fluorescence microscope and immunohistochemical analysis. After hematoxylin and eosin (HE) staining and Masson's Trichrome (MT) staining, histomorphometric analysis was performed to evaluate bone regeneration. RESULTS: In both groups transplanted with BMSCs, the number of GFP-positive BMSCs detected in the bone defects reached its peak at 1 week after surgery and was decreased thereafter. However, at all time points, less GFP+ cells were detected in the ApoE-/- mice than in the corresponding control mice. BMSCs transplantation significantly enhanced new bone formation, but to a lesser degree in the ApoE-/- mice when compared with the control mice. CONCLUSIONS: Hyperlipidemia compromises homing efficiency of systemically transplanted BMSCs and inhibits bone regeneration.

Systemically transplanted human gingiva-derived mesenchymal stem cells contributing to bone tissue regeneration.

As novel postnatal stem cells, gingiva-derived mesenchymal stem cells (GMSCs) have been considered as an ideal candidate cell resource for tissue engineering and cell-based therapies. GMSCs implanted into sites of injury have been confirmed to promote the injury repair. However, no studies have demonstrated whether systemically transplanted GMSCs can home to the bone injuries and contribute to the new bone formation in vivo. In this study, we transplanted human GMSCs into C57BL/6J mice with defects in mandibular bone via the tail vein to explore the capacity of transplanted GMSCs to promote bone regeneration. Results showed that the transplanted GMSCs were detected in the bone defects and employed in new bone formation. And the newly formed bone area in mice with GMSCs transplantation was significantly higher than that in control mice. Our findings indicate that systemically transplanted GMSCs can not only home to the mandibular defect but also promote bone regeneration.

Effect of umbilical cord mesenchymal stem cell in peri-implant bone defect after immediate implant: an experiment study in beagle dogs.

BACKGROUND: For the sake of reducing post extraction resorption, getting optimal positioning of the implant and shortening treatment time, immediate implant placement following tooth extraction has been proposed as a treatment option. However, the large bone defect peri-implant has a negative influence on the process of bone healing. In this study, umbilical cord mesenchymal stem cells (UCMSCs) were transplanted into the bone defect peri-implant inbeagle dogs and the effect of UCMSCs on bone regeneration in peri-implant were assessed. METHODS: The mandibular second, third and fourth premolars of 8 beagle dogs were extracted bilaterally. The defects in one side were filled with platelet-rich fibrin (PRF) and then UCMSCs were injected into the defect area, while the defects in the other side were filled with PRF only as control group. The titanium implant was placed into the distal root socket of each extracted tooth. The animals were sacrificed at week 2, 4 and 8 post operative. The bone defects adjacent to the implant which are 4 mm in height, 4 mm in the mesio-distal direction and 3.5 mm in the bucco-lingual direction were made after immediate implant. Histomorphometric analysis was performed using methylene blue-fuchsin acid staining and hematoxylin and eosin (HE) staining to evaluate bone regeneration. RESULTS: The direct bone-to-implant contact (BIC) in the experiment after 4 and 8 weeks was 56.47±1.18% and 76.23±2.08%; and in the control group was40.79±0.65% and 61.17±2.79%, respectively. The percentage of newly formed bone after 2, 4 and 8 weeks was 17.60±1.5%, 49.82±4.02% and 67.16±2.1% in experiment group; and in control group 14.30±1.25%, 37.04±2.29% and 58.83±3.36%, respectively. These results represented significant differences statistically. CONCLUSION: Intra-bone marrow injection of UCMSCs can promote new bone formation. UCMSCs can be used to as excellent seed cells to repair the large defect peri-implant after immediate implant.

Effect of umbilical cord mesenchymal stem cell in peri-implant bone defect after immediate implant: an experiment study in beagle dogs.

BACKGROUND: For the sake of reducing post extraction resorption, getting optimal positioning of the implant and shortening treatment time, immediate implant placement following tooth extraction has been proposed as a treatment option. However, the large bone defect peri-implant has a negative influence on the process of bone healing. In this study, umbilical cord mesenchymal stem cells (UCMSCs) were transplanted into the bone defect peri-implant in beagle dogs and the effect of UCMSCs on bone regeneration in peri-implant were assessed. METHODS: The mandibular second, third and fourth premolars of 8 beagle dogs were extracted bilaterally. The defects in one side were filled with platelet-rich fibrin (PRF) and then UCMSCs were injected into the defect area, while the defects in the other side were filled with PRF only as control group. The titanium implant was placed into the distal root socket of each extracted tooth. The animals were sacrificed at week 2, 4 and 8 post operation. The bone defects adjacent to the implant which are 4 mm in height, 4 mm in the mesio-distal direction and 3.5 mm in the bucco-lingual direction were made after immediate implant. Histomorphometric analysis was performed using methylene blue-fuchsin acid staining and hematoxylin and eosin (HE) staining to evaluate bone regeneration. RESULTS: The direct bone-to-implant contact (BIC) in the experiment after 4 and 8 weeks was 56.47 ± 1.18% and 76.23 ± 2.08%; and in the control group was40.79 ± 0.65% and 61.17 ± 2.79%, respectively. The percentage of newly formed bone after 2, 4 and 8 weeks was 17.60 ± 1.5%, 49.82 ± 4.02% and 67.16 ± 2.1% in experiment group; and in control group 14.30 ± 1.25%, 37.04 ± 2.29% and 58.83 ± 3.36%, respectively. These results represented significant differences statistically. CONCLUSION: Intra-bone marrow injection of UCMSCs can promote new bone formation. UCMSCs can be used to as excellent seed cells to repair the large defect peri-implant after immediate implant.

[Cytocompatibility of chitosan-based thermosensitive hydrogel to human periodontal ligament cell].

PURPOSE: The aim of this investigation was to evaluate the cytocompatibility of an in situ chitosan-quaternized chitosan/α, ß-glycerophosphate (CS-HTCC/GP) thermosensitive hydrogel in vitro. METHODS: The primary cells were isolated from human periodontal ligament and cultured. The role of different concentrations of CS-HTCC/GP extract to HPDLCs was evaluated by MTT assay and alkaline phosphatase (ALP) activity. Also, the ultra-architecture of HPDLCs was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. SPSS13.0 software package was used for statistical analysis. RESULTS: By immunocytochemical method, the cells were stained positively to antibodies against vimentin, and negatively to antibodies against cytokeratin, which indicated that they were external embryo mesenchymal cell without epithelial cell mixure. CS-HTCC/GP thermosensitive hydrogel promoted proliferation of HPDLCs,especially at 3d and 5d, the results was significantly different (P<0.001). ALP activity was significantly greater in group 2 and 3 than in group 4 after 5d (P<0.001). Also, no negative influence to ultrastructure of HPDLCs was found through SEM and TEM. CONCLUSIONS: The results indicate that CS-HTCC/GP thermosensitive hydrogel exhibits excellent cytocompatibility and has potential to be used as an in situ injectable local periodontal drug delivery vehicle and a tissue-engineering scaffold for periodontal disease therapy.

[Effect of the tumescent infiltration solution temperature on body temperature].

OBJECTIVE: To evaluate the effect of tumescent infiltration solution temperature on core body temperature after liposuction. METHODS: 15 healthy female subjects were randomly divided into 2 groups to receive tumescent infiltration solution at 25 degrees C as group A, or at 37 degrees C as group B. All subjects were under epidural anesthesia. Vital signs, including core temperature, heart rate, respiratory rate and blood pressure, were monitored immediately, 1 hour, 2 hours, 3 hours, 4 hours and 8 hours after operation. RESULTS: The core body temperature immediately, 1 hour, 2 hours and 3 hours after operation were (35.8 +/- 0.5) degrees C, (35.8 +/- 0.5) degrees C, (36.0 +/- 0.5) degrees C, (36.1 +/- 0.5) degrees C in group A, and (36.5 +/- 0.4) degrees C, (36.5 +/- 0.3) degrees C, (36.5 +/- 0.3) degrees C, (36.6 +/- 0.4) degrees C in group B, showing a significant difference between the two groups (P = 0.008, P = 0.008, P = 0.03, P = 0.033, respectively). There was no difference in body temperature 4 hours and 8 hours after operation and in heart rate, respiratory rate and blood pressure between the two groups (P > 0. 05). CONCLUSIONS: The tumescent infiltration solutions at room temperature (25 degrees C) can decrease the core body temperature and increase surgical risk. It might not be good for rehabilitation. It is recommended to use tumescent infiltration solution at body temperature (37 degrees C) in liposuction.

[An in vitro evaluation of the antibacterial activity of chitosan-based thermosensitive hydrogel against periodontal pathogens].

PURPOSE: To evaluate the in vitro antibacterial activity of chitosan - quaternized chitosan/alpha, beta-glycerophosphate (CS-HTCC/GP) thermosensitive hydrogel against three periodontal pathogens- P. gingivalis, P. intermedia, and A. actinomycetemcomitans. METHODS: An agar diffusion method was used to assess the antimicrobial property of CS-HTCC/GP thermosensitive hydrogel with minimum inhibitory concentration (MIC) and inhibitory zone measurement. SPSS13.0 software package was used for Student's t test. RESULTS: Three periodontal pathogens strains were all susceptible to CS-HTCC/GP thermosensitive hydrogel. Both matrix of thermosensitive hydrogel and antibiotic exhibited stronger antibacterial activity especially when they were combined. CONCLUSIONS: CS-HTCC/GP thermosensitive hydrogel is not only as the vehicle of antibiotics which joins the local drug delivery system but as an activator which takes part in the antibacterial process.

[Application of hatchet flap for buccal tissue defect].

OBJECTIVE: To evaluate the therapeutic effect of hatchet flap for buccal tissue defect. METHODS: The hatchet flap was designed beside the tissue defect and advanced to cover the defect. RESULTS: Since 2006, 13 cases were treated with primary healing and no flap loss. The size of the flaps ranged from 1.8 cm x 2.0 cm to 2.5 cm x 3.5 cm. All the cases were followed up for 3 months to 1.5 years. The postoperative appearance was satisfactory with inconspicuous scar. CONCLUSIONS: Hatchet flap is very suitable for the buccal tissue defect with satisfactory cosmetic result. The facial natural figure is protected very well.

Plasma protein adsorption pattern and tissue-implant reaction of poly(vinyl alcohol)/carboxymethyl-chitosan blend films.

Various poly(vinyl alcohol)/carboxymethyl-chitosan (PVA/CMCS) blend films were prepared by a mechanical blending method and characterized by SEM for their surface and cross-section morphologies. It indicated that blending high CMCS content in PVA plastic led to a rough surface and loose structure. Bovine serum albumin (BSA) and bovine fibrinogen (BFG) were chosen as representative plasma proteins to carry out adsorption tests. Equilibrium adsorption amount of proteins onto the blends decreased with the increase of CMCS content in film matrix, and BSA was more easily adsorbed onto the films than BFG in the same conditions. The blend films also exhibited different trends for BSA and BFG adsorption when pH of the media changed, but maximum adsorption approximately occurred at the isoelectric point of proteins. Moreover, increasing the ionic strength would always decrease the adsorptions of protein onto the films. In animal experiments, it was found that incorporation of CMCS and PVA gave a lower tissue reaction than pure PVA films when they were subcutaneously implanted in Wistar rats. After two weeks subcutaneous implantation, surfaces of PVA became wrinkled and cracked; however, the blend implants exhibited a alveolate porous microstructure.

Study on poly(vinyl alcohol)/carboxymethyl-chitosan blend film as local drug delivery system.

The distinguishable films composed of poly(vinyl alcohol) (PVA) and carboxymethyl-chitosan (CMCS) were prepared by blending/casting method, and loaded with ornidazole (OD) as local drug delivery system. In vitro test, the blend films showed pH-responsive swelling behavior and moderate drug release action, and also exhibited a little antimicrobial activity against E. coli and S. aureus strains. Those characteristics of CMCS/PVA blend films were essentially governed by the weight ratio of CMCS and PVA. Increasing the content of PVA in blend film would decrease swelling and decelerated the drug release. However, increasing the content of CMCS would enhance the antimicrobial activity. The biocompatibility and bioactivity of the blend film were also evaluated using rabbit blood and Wister rats. This blend drug system was of no hemolysis, no toxicity to rat periodontia and no cytotoxicity to the rat muscle. After subcutaneously implanting the blend drug films in Wister rat, the systems kept a good retention at the application site and maintained high drug concentration in long time (5 days) which was longer than the period of drug released in vitro (160 min).