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.
Objective To design and construct a graphene oxide (GO)/silver nitrate (Ag3PO4)/chitosan (CS) composite coating for rapidly killing bacteria and preventing postoperative infection in implant surgery. Methods GO/Ag3PO4 composites were prepared by ion exchange method, and CS and GO/Ag3PO4 composites were deposited on medical titanium (Ti) sheets successively. The morphology, physical image, photothermal and photocatalytic ability, antibacterial ability, and adhesion to the matrix of the materials were characterized. Results The GO/Ag3PO4 composites were successfully prepared by ion exchange method and the heterogeneous structure of GO/Ag3PO4 was proved by morphology phase test. The heterogeneous structure formed by Ag3PO4 and GO reduced the band gap from 1.79 eV to 1.39 eV which could be excited by 808 nm near-infrared light. The photothermal and photocatalytic experiments proved that the GO/Ag3PO4/CS coating had excellent photothermal and photodynamic properties. In vitro antibacterial experiments showed that the antibacterial rate of the GO/Ag3PO4/CS composite coating against Staphylococcus aureus reached 99.81% after 20 minutes irradiation with 808 nm near-infrared light. At the same time, the composite coating had excellent light stability, which could provide stable and sustained antibacterial effect. ConclusionGO/Ag3PO4/CS coating can be excited by 808 nm near infrared light to produce reactive oxygen species, which has excellent antibacterial activity under light.
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.
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.
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.
Objective To investigate the antibacterial and osteogenic capabil ities in vivo of hydroxyapatite (HA)/silver (Ag) coating. Methods HA/Ag coating (Ag qual ity percentage was 3%) and HA coating were deposited to external fixator Schanz screws. The tibial fracture model was establ ished in right hindl imb of 18 adult male Beagle dogs (weighing 15-20 kg). Thetibia was stabil ized with an external fixator and 2 Schanz screws of HA coating at proximal tibia (control group, n=18) and HA/Ag coating at distal tibia (experimental group, n=18), and every screw incision was infected with Staphylococcus aureus. Infection in screw holes and the changes of bone-screw interface were observed by wound grading and X-ray films. Results In control group, wounds infection became worse with time (χ2=13.492, P=0.001), while in experimental group, no obvious change was observed (χ2=0.208, P=0.901). The wound grading of experimental group was significantly better than that of the control group at 1, 2, and 3 weeks (P lt; 0.05). Laser scanning confocal microscope showed that there was bacterial adhesion on the surface of screws in 2 groups, viable becteria mainly in control group and non-viable becteria mainly in experimental group. The scanning electron microscope (SEM) observation results of the fractured sclerous tissue section showed that an obvious transparent boundary between screw and bone in control group, but no obvious boundary in experimental group. The osseointegration ratios were 76.23% ± 15.54% in control group and 93.42% ± 5.53% in experimental group, showing significant difference (t=8.843, P=0.000). The SEM observation showed that HA/Ag coating integrated with new bone and the surface of implant was filled with new bone in experimental group; obvious interspace was seen between the HA coating and new bone in control group. Conclusion HA/Ag coating has good antibacterial and osteogenic capabil ities, so it can take effects in preventing infection in screw holes and loosening of implants.
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.
Objective To investigate the physicochemical properties of pure titanium surface grafted with chlorhexidine (CHX) by phenolamine coating, and to evaluate its antibacterial activity and osteoblast-compatibility in vitro. MethodsControl group was obtained by alkali and thermal treatment, and then immersed in the mixture of epigallocatechin-3-gallate/hexamethylene diamine (coating group). Phenolamine coating was deposited on the surface, and then it was immersed in CHX solution to obtain the grafted surface of CHX (grafting group). The surface morphology was observed by scanning electron microscope, the surface element composition was analyzed by X-ray photoelectron spectroscopy, and the surface hydrophilicity was measured by water contact angle test. Live/dead bacterial staining, nephelometery, and inhibition zone method were executed to evaluate the antibacterial property. Cytotoxicity was evaluated by MTT assay and cell fluorescence staining. Bacteria-MC3T3-E1 cells co‐culture was conducted to evaluate the cell viability on the samples under the circumstance with bacteria. Results Scanning electron microscope observation results showed that deposits of coating group and grafting group increased successively and gradually covered the porous structure. X-ray photoelectron spectroscopy results showed the peak of N1s enhanced and the peak of Cl2p appeared in grafting group. Water contact angle test results showed that the hydrophilic angle of three groups increased in turn, and there was significant difference between groups (P<0.05). Live/dead bacteria staining results showed that the grafting group had the least amount of bacteria adhered to the surface and the proportion of dead bacteria was high. The grafting group had a transparent inhibition zone around it and the absorbance (A) value did not increase, showing significant difference when compared with control group and coating group (P<0.05). MTT assay and cell fluorescence staining results showed that the number of adherent cells on the surface of the grafting group was the least, but the adherent cells had good proliferation activity. Bacteria-cell co-culture results showed that there was no bacteria on the surface of grafting group but live cells adhered well. ConclusionCHX-grafted phenolamine coating has the ability to inhibit bacterial adhesion and proliferation, and effectively protect cell adhesion and proliferation in a bacterial environment.
ObjectiveTo review the research progress of cementless intercalary prosthesis stem. MethodsThe literature about the cementless intercalary prosthesis in treatment of bone defects of extremities was reviewed, and the designing and application of prosthesis stem were analyzed. ResultsCementless intercalary prosthesis has the advantages of good biocompatibility. However, there are also some disadvantages, including the multiple factors affecting the fixation of the prosthesis stem and individual differences in the stability of the prosthesis. The methods to improve the fixation stability of prosthesis stem mainly include the optimization of prosthesis stem shape, addition of auxiliary fixation, and improvement of coating materials on the stem surface as well as porous structure of the stem surface. Among these methods, augment with auxiliary fixation has the most satisfactory effect on improving the stability of prosthesis. However, the deficiency of the method is the increasing risk of the larger incision exposure and surgical trauma. ConclusionImproving the design and fixation method of the cementless intercalary prosthesis stem can further improve the stability of the prosthesis. Under the premise of avoiding increasing surgical trauma as much as possible, addition of the auxiliary fixation can be a feasible choice to improve the fixation stability of prosthesis.