Zeyuan Lei

Osteopontin (OPN) Is an Important Protein to Mediate Improvements in the Biocompatibility of C Ion-Implanted Silicone Rubber

Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface.

Role of serum amyloid P in skin graft survival and wound healing in burned patients receiving skin grafts.

BACKGROUND Recent studies in animal models suggest that serum amyloid P (SAP) can affect burn wound healing. However, the role of SAP in a clinical setting remains unknown. METHODS We enrolled 88 patients with third degree burn wounds. All the patients were candidates for auto-skin graft procedure using stamp skin graft. The complete graft healing time and the number of survived grafts were recorded. Serum SAP levels were assessed 1 day before operation. RESULTS There was no significant difference in SAP level between controls and patients. There were no significant differences noted among the patients with different burn surface area. However, when the patients in each group were stratified by SAP levels, the mean complete healing time of grafted wound and the mean numbers of survived skin grafts were significantly different. Spearmans analyses showed that the serum SAP levels negatively correlated with the complete wound healing time and mean numbers of survived skin grafts. Logistic regression analysis showed that the serum SAP levels and mean numbers of survived skin grafts were potent independent factors contributing to wound healing. CONCLUSIONS The results of this study suggest that the serum SAP levels may be an easy detected predictor for the healing of burn wounds.

Biofunctionalization of silicone rubber with microgroove-patterned surface and carbon-ion implantation to enhance biocompatibility and reduce capsule formation

Purpose Silicone rubber implants have been widely used to repair soft tissue defects and deformities. However, poor biocompatibility can elicit capsule formation, usually resulting in prosthesis contracture and displacement in long-term usage. To overcome this problem, this study investigated the properties of silicone rubber materials with or without a microgroove-patterned surface and with or without carbon (C)-ion implantation. Materials and methods Atomic force microscopy, X-ray photoelectron spectroscopy, and a water contact angle test were used to characterize surface morphology and physicochemical properties. Cytocompatibility was investigated by a cell adhesion experiment, immunofluorescence staining, a Cell Counting Kit-8 assay, and scanning electron microscopy in vitro. Histocompatibility was evaluated by studying the inflammatory response and fiber capsule formation that developed after subcutaneous implantation in rats for 7 days, 15 days, and 30 days in vivo. Results Parallel microgrooves were found on the surfaces of patterned silicone rubber (P-SR) and patterned C-ion-implanted silicone rubber (PC-SR). Irregular larger peaks and deeper valleys were present on the surface of silicone rubber implanted with C ions (C-SR). The silicone rubber surfaces with microgroove patterns had stable physical and chemical properties and exhibited moderate hydrophobicity. PC-SR exhibited moderately increased dermal fibroblast cell adhesion and growth, and its surface microstructure promoted orderly cell growth. Histocompatibility experiments on animals showed that both the anti-inflammatory and antifibrosis properties of PC-SR were slightly better than those of the other materials, and there was also a lower capsular contracture rate and less collagen deposition around implants made from PC-SR. Conclusion Although the surface chemical properties, dermal fibroblast cell growth, and cell adhesion were not changed by microgroove pattern modification, a more orderly cell arrangement was obtained, leading to enhanced biocompatibility and reduced capsule formation. Thus, this approach to the modification of silicone rubber, in combination with C-ion implantation, should be considered for further investigation and application.

Hydroxyapatite-Coated Sillicone Rubber Enhanced Cell Adhesion and It May Be through the Interaction of EF1β and γ-Actin

Silicone rubber (SR) is a common soft tissue filler material used in plastic surgery. However, it presents a poor surface for cellular adhesion and suffers from poor biocompatibility. In contrast, hydroxyapatite (HA), a prominent component of animal bone and teeth, can promote improved cell compatibility, but HA is an unsuitable filler material because of the brittleness in mechanism. In this study, using a simple and economical method, two sizes of HA was applied to coat on SR to counteract the poor biocompatibility of SR. Surface and mechanical properties of SR and HA/SRs confirmed that coating with HA changes the surface topology and material properties. Analysis of cell proliferation and adhesion as well as measurement of the expression levels of adhesion related molecules indicated that HA-coated SR significantly increased cell compatibility. Furthermore, mass spectrometry proved that the biocompatibility improvement may be related to elongation factor 1-beta (EF1β)/γ-actin adjusted cytoskeletal rearrangement.

The use of expanded polytetrafluoroethylene in depressed deformities of the face.

Expanded polytetrafluoroethylene (ePTFE) has been extensively used for facial soft tissue augmentation procedures, and is regarded as safe and reliable and suitable as a permanent implant. This implant is generally used in the lower third of the face for lips filling, nasal augmentation, nasolabial folds and chin augmentation, and rarely for congenital or acquired depressed deformities of the face. The aim of the present study was to assess the effects of ePTFE in congenital or acquired depressed deformities of the face. From September, 2008 to January, 2014, 26 patients were implanted with the material ePTFE to correct depressed deformities of the face. The average age at operation was 23.2 years, with a range of 17–45 years. The depressed deformities were lateralized. The follow-up period was 6–18 months (average 9 months). The etiologies of the depressed deformities included stable hemifacial atrophy (3 cases), craniofacial microsomia (13 cases), bony depression after trauma (8 cases), and other unclear reasons (2 cases). The operations were performed under local anesthesia. ePTFE was inserted in different tissue planes that varied among the different subanatomical areas in the face: beneath the superficial temporal fascia in the temporal area, and on the surface of the superficial musculoaponeurotic system in the zygomatic area, cheek and mandibular area. All of the patients were followed up. Most of the patients [25 of 26 patients (96.2%)] were satisfied with the results, while 1 patient (3.8%) was not satisfied for incomplete correction of the depressed deformity. In conclusion, aside from lipofilling and a free flap transfer, the results showed that ePTFE was an alternative treatment for facial depressed deformity.

Complications from Nasolabial Fold Injection of Calcium Hydroxylapatite for Facial Soft-Tissue Augmentation: A Systematic Review and Meta-Analysis

BACKGROUND Despite its increasing usage of facial applications, there is a paucity of objective data regarding calcium hydroxylapatite (CaHA). OBJECTIVES To systematically evaluate the complications from CaHA injection for facial soft tissue augmentation. METHODS Published studies on CaHA injection for facial soft tissue enhancement were identified through searches of the PubMed, EMBASE, and Cochrane Controlled Trial databases. Only randomized, controlled trials comparing CaHA injection to either placebo or an active comparator for facial cosmetic use were included. The outcome measures were the count (n) and frequency (%) of each complication, including edema (swelling), erythema (redness), ecchymosis (bruising), pain, pruritus (itching), hematomas, nodules, and extrusions. RESULTS Four studies on nasolabial fold (NLF) injection of CaHA consisting of two subgroups were included: (i) a CaHA-lidocaine vs CaHA subgroup and (ii) a CaHA vs hyaluronic acid (HA) subgroup. The addition of lidocaine to CaHA therapy displayed no significant effect on edema (RR (95% CI): 1.07 (0.94-1.21), P = .311), erythema (RR (95% CI): 0.91 (0.66-1.24), P = .544), ecchymosis (RR (95% CI): 1.04 (0.71-1.52), P = .843), pain (RR (95% CI): 0.88 (0.58-1.33), P = .553), or pruritus (RR (95% CI): 0.82 (0.45-1.50), P = .515). There was no significant difference between CaHA vs HA for hematomas (RR (95% CI): 0.24 (0.01-4.31), P = .332) or nodules (RR (95% CI): 0.18 (0.01-6.62), P = .353). There was no significant publication bias detected in either subgroup (Beggs test P > 0.05). CONCLUSIONS These findings support the addition of lidocaine to NLF injection of CaHA and suggest an equivalence between CaHA and HA with respect to hematoma and nodule formation. LEVEL OF EVIDENCE 2: Risk.