Objective To understand the value of pre-coating in artificial vessel endothelialization. Methods Literature concerning precoating in artificial vessel endothelialization was extensively reviewed. Results Pre-coating included chemical coatings(collagen, fibronectin, laminin, poly-l-lysin, gelatin andextracellular matrix), pre-clotting(plasma, blood, serum and fibrin glue), chemical bonding (heparin, RGD and lectins) and surface modification. Most of them could enhance the adhesion of the endothelial cells. Conclusion Pre-coating couldimprove endothelialization, but further research is needed to search for the appropriate concentration and incubation time.
Compound Huangbai liquid coating agent is a preparation that combines multiple traditional Chinese medicinal herbs and has shown significant efficacy in burn treatment. In recent years, the application of this coating agent in burn treatment has received widespread attention, and it plays a role in promoting wound healing, preventing infection, and reducing patient pain. This article reviews the research progress of compound Huangbai liquid coating agent in burn treatment, explores its mechanism of promoting wound healing, evaluates its current advantages and limitations in burn treatment, and provides scientific basis and theoretical support for its better use in burn treatment.
ObjectiveTo review the current research and application progress of three-dimentional (3D) printed porous titanium alloy after tumor resection, and provide direction and reference for the follow-up clinical application and basic research of 3D printed porous titanium alloy. MethodsThe related literature on research and application of 3D printed porous titanium alloy after tumor resection in recent years was reviewed from three aspects: performance of simple 3D printed porous titanium alloy, application analysis of simple 3D printed porous titanium alloy after tumor resection, and research progress of anti-tumor 3D printed porous titanium alloy. Results3D printing technology can adjust the pore parameters of porous titanium alloy, so that it has the same biomechanical properties as bone. Appropriate pore parameters are conducive to inducing bone growth, promoting the recovery of skeletal system and related functions, and improving the quality of life of patients after operation. Simple 3D printed porous titanium alloy can more accurately match the bone defect after tumor resection through preoperative personalized design, so that it can closely fit the surgical margin after tumor resection, and improve the accuracy and efficiency of the operation. The early and mid-term follow-up results show that its application reduces the postoperative complications such as implant loosening, subsidence, fracture and so on, and enhances the bone stability. The anti-tumor performance of 3D printed porous titanium alloy mainly includes coating and drug-loading treatment of pure 3D printed porous titanium alloy, and some progress has been made in the basic research stage. ConclusionSimple 3D printed porous titanium alloy is suitable for patients with large and complex bone defects after tumor resection, and the anti-tumor effect of 3D printed porous titanium alloy can be achieved through coating and drug delivery.
Objective To investigate the research progress of drug-loaded antibacterial coating of orthopedic metal implants in recent years. Methods The recent literature on the drug-loaded antibacterial coating of orthopedic metal implants were reviewed. The research status, classification, and development trend of drug-loaded antibacterial coating were summarized. Results The drug-loaded antibacterial coating of orthopedic metal implants can be divided into passive release type and active release type according to the mode of drug release. Passive drug release coating can release the drug continuously regardless of whether the presence of bacteria around the implants. Active drug release coating do not release the drug unless the presence of bacteria around the implants. Conclusion The sustained and stable release of drugs is a key problem to be solved in various antibacterial coatings research. The intelligent antibacterial coating which release antibiotics only in the presence of bacteria is the future direction of development.
A diblock copolymer, poly(ethylene glycol) methacrylate-block-glycidyl methacrylate (PEGMA-GMA), was prepared on glass substrate by surface-initiated atom transfer radical polymerization (SI-ATRP), and endothelial specific peptide Arg-Glu-Asp-Val (REDV) was immobilized at the end of the PEGMA-GMA polymer brush by ring opening reaction through the rich epoxy groups in the GMA. The structure and hydrophilicity of the polymer brushes were characterized by static water contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results showed that the REDV modified copolymer brushes were successfully constructed on the glass substrates. The REDV peptide immobilized onto surface was quantitatively characterized by ultraviolet–visible spectroscopy (UV-VIS). The blood compatibility of the coating was characterized by recalcification time and platelet adhesion assay. The results showed that the polymer coating had good blood compatibility. The multifunctional active polymer coating with PEGMA and peptide produced an excellent prospect in surface construction with endothelial cells selectivity.
Objective To prepare silver-containing hydroxyapatite coating (hydroxyapatite/Ag, HA/Ag) and investigate its antibacterial property and biocompatibil ity in vitro. Methods Vacuum plasma spraying technique was adopted to prepare HA/Ag coating on titanium alloy substrate (3% Ag). After incubating the HA/Ag and the HA coating under staphylococcus aureus and pseudomonas aeruginosa suspensions of 2% tryptic soy broth (TBS) medium for 2, 4 and 7 days, respectively, the biofilm on the coatings was examined by confocal laser scanning microscope, and the bacterial density and viable bacterial percentage of bacterial biofilm were calculated. Meanwhile, the micro-morphology of bacterial biofilm was observed by SEM, the cytotoxicity was detected via MTT and the biocompatibil ity of biofilm was evaluated by acute aemolysis test. Results Compared with HA coating, the bacterial biofilm’s thickness on the surface of HA/Ag coating witnessed no significant difference at 2 days after culture (Pgt; 0.05), but decreased obviously at 4 and 7 days after culture (P lt; 0.01). The bacterial density of the biofilm increased with time, but there was no significant difference between two coatings (P gt; 0.05) at 2, 4 and 7 days after culture. The viable bacterial percentage of the biofilms on the surface of HA/Ag coating decreased obviously compared with that of HA coating at 2, 4 and 7 days after cultureP lt; 0.01). The MTT notified the cytotoxic grade of both coatings was zero. The acute haemolysis assay showed that the hemolytic rate of HA/Ag and HA coating was 0.19% and 0.12%, respectively. Conclusion With good biocompatibil ity, significant antibacterial property against staphylococcus aureus and pseudomonas aeruginosa, no obvious cytotoxicity and no erythrocyte destruction, the vacuum plasma sprayed HA/Ag coating is a promising candidate for the surface of orthopedic metal implants to improve their osseointegration and antibacterial property.
Objective Surface modification of nitinol (NiTi) shape memory alloy is an available method to prevent nickel ion release and coating with titanium-niobium (TiNb) alloy will not affect the superelasticity and shape memory of NiTi. To evaluate the bone histocompatibil ity of NiTi shape memory alloy implants coated by TiNb in vivo. Methods NiTi memory alloy columns which were 4 mm in diameter and 12 mm in length were coated with Ti (Ti-coating group) and TiNb alloy (TiNb-coating group) respectively by magnetron sputtering technique. And NiTi group were not coated on the surface. Fifteen mongrel dogs were divided into 3 groups randomly with 5 dogs in each group. NiTi, Ti-coating and TiNb-coating columns were implanted into the lateral femoral cortex of each group, respectively. There were 10 columns embedded in eachdog’s femur whose distance was 1.0 cm to 1.5 cm from each other. The materials were obtained 12 months after operation. After X-ray photography, only those columns which were perpendicular to the cortex of the femur shaft were selected for subsequent analysis. Push-out tests were performed to attain the maximum shear strength (the number of specimens of TiNi group, Ticoating group, and TiNb-coating group were 12, 10, and 14, respectively). Undecalcified sections were used for histological observation and the calculation of osseointegration rate (the number of specimens of TiNi group, Ti-coating group, and TiNb-coating group were 8, 5, and 10, respectively). Results The maximum shear strength of Ti-coating group (95.10 ± 10.03) MPa, and TiNb-coating group (91.20 ± 15.42) MPa were significantly higher than that of NiTi group (71.60 ± 14.24) MPa (P lt; 0.01). Gimesa staining showed that no obvious macrophage and inflammation cell was observed in 3 groups. The osseointegration rates of NiTi group, Ti-coating group, and TiNb-coating group were (21.30% ± 0.23%), (32.50% ± 0.31%), and (38.60% ± 0.58%), respectively; there were significant differences among 3 groups (P lt; 0.01). Conclusion The implants of 3 groups all have good bone histocompatabil ity. But the osseointegration rate and the shear strength in the Ti-coating group and the TiNb-coating group were better than those in the NiTi group, the TiNb-coating group is the best among them.
Implantation of drug-eluting stents (DES) is one of the most effective treatment for intraluminal vascular diseases such as vascular stenosis caused by atherosclerosis. Antiproliferative drugs offered by could significantly reduce the restenosis of blood vessels, which is beneficial to interventional therapy in more advanced and complex vascular diseases. This review sumarizes the state-of-the-art of the DES based on the function of loaded drug and material of the stents. We hope this review can provide basic information of DES for clinicians and researchers to make more rational choices in practical applications. Moreover, this review also propses the prospects of drug-loaded stents.
An oxide ceramic coating can be formed on the surface of magnesium alloy by micro-arc oxidation so that the corrosion resistance of the magnesium alloy can be enhanced. In this paper, a general overview of the surface treatment of micro-arc oxidation on the surface of magnesium alloy is presented, the related research on the treatment of several kinds of magnesium alloys is introduced in detail, and a brief introduction of biological activity of magnesium alloy due to micro-arc oxidation is given. Finally, the technical advantages and existing problems are summarized.
ObjectiveTo review antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants, so as to provide reference for subsequent research. MethodsThe related research literature on antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants in recent years was reviewed, and the research progress was summarized based on different kinds of antibacterial substances and osteogenic active substances. ResultsAt present, the antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants includes: ① Combined coating strategy of antibiotics and osteogenic active substances. It is characterized in that antibiotics can be directly released around titanium-based implants, which can improve the bioavailability of drugs and reduce systemic toxicity. ② Combined coating strategy of antimicrobial peptides and osteogenic active substances. The antibacterial peptides have a wide antibacterial spectrum, and bacteria are not easy to produce drug resistance to them. ③ Combined coating strategy of inorganic antibacterial agent and osteogenic active substances. Metal ions or metal nanoparticles antibacterial agents have broad-spectrum antibacterial properties and various antibacterial mechanisms, but their high-dose application usually has cytotoxicity, so they are often combined with substances that osteogenic activity to reduce or eliminate cytotoxicity. In addition, inorganic coatings such as silicon nitride, calcium silicate, and graphene also have good antibacterial and osteogenic properties. ④ Combined coating strategy of metal organic frameworks/osteogenic active substances. The high specific surface area and porosity of metal organic frameworks can effectively package and transport antibacterial substances and bioactive molecules. ⑤ Combined coating strategy of organic substances/osteogenic active substancecs. Quaternary ammonium compounds, polyethylene glycol, N-haloamine, and other organic compounds have good antibacterial properties, and are often combined with hydroxyapatite and other substances that osteogenic activity. ConclusionThe factors that affect the antibacterial and osteogenesis properties of titanium-based implants mainly include the structure and types of antibacterial substances, the structure and types of osteogenesis substances, and the coating process. At present, there is a lack of clinical verification of various strategies for antibacterial/osteogenesis dual-functional surface modification of titanium-based implants. The optimal combination, ratio, dose-effect mechanism, and corresponding coating preparation process of antibacterial substances and bone-active substances are needed to be constantly studied and improved.