Effect of electrochemically dealloying Ti6Al4V abutments on human gingival fibroblasts / 口腔疾病防治

Objective@#To investigate the effects of electrochemically dealloying of Ti6Al4V abutments on human gingival fibroblasts (HGFs) and to provide experimental evidence for surface modification of implant abutments.@*Methods@#The samples were divided into an NC group (negative control, no other treatment on a smooth surface), an NM-1 group (nanomesh-1, electrochemical dealloying treatment in 1 mol/L NaOH 1 h on 2 V voltage), and an NM-2 group (nanomesh-2, electrochemical dealloying treatment in 5 mol/L NaOH 1 h on 2 V voltage). The surface morphologies of the samples and the adhesion of HGFs on the sample surfaces were observed with scanning electron microscopy (SEM). The surface hydrophilicities of the samples were measured with a contact angle measuring instrument. The proliferation of HGFs on the different samples were evaluated with CCK-8, and the expression of adhesion-related genes, including collagen Ⅰ (COL1A1), collagen Ⅲ (COL3A1), fibronectin 1 (FN1), focal adhesion kinase (FAK), vinculin (VCL), integrin α2 (ITGA2), and integrin β1 (ITGB1), on the different samples was measured with qRT-PCR. The expression of vinculin on the surfaces of HGFs was observed via confocal laser scanning microscopy (CLSM) after immunofluorescent staining. Collagen fiber secretion and syntheses of HGFs from different samples were evaluated via Sirius red staining.@*Results@#SEM revealed the formation of ordered and uniform three-dimensional mesh structures on the surfaces of the NM-1 and NM-2 groups, with grid diameters of approximately 30 nm for the NM-1 group and approximately 150 nm for the NM-2 group. Compared with that of the NC group, the water contact angles of the NM-1 group and NM-2 groups were significantly lower (P<0.000 1). Cell proliferation in the NM-1 group was significantly greater than that in the NC group (P<0.01). Moreover, there was no significant difference in the water contact angles or cell proliferation between the NM-1 group and the NM-2 group. SEM revealed that HGFs were adhered well to the surfaces of all samples, while the HGFs in the NM-1 and NM-2 groups showed more extended areas, longer morphologies, and more developed pseudopodia than did those in the NC group after 24 h. qRT-PCR revealed that the expression levels of the adhesion-related genes COL1A1, COL3A1, FN1, FAK and VCL in the NM-1 group were significantly greater than those in the NC and NM-2 groups (P<0.01). The expression of vinculin protein in the NM-1 group was the highest, and the number of focal adhesions was greatest in the NM-1 group (P<0.01). The results of Sirius red staining showed that the NM-1 group had the highest secretion and syntheses of collagen fibers (P<0.000 1).@*Conclusion@#The three-dimensional nanomechanical structure of Ti6Al4V modified by electrochemical dealloying promoted the adhesion, proliferation, collagen fiber secretion and syntheses of HGFs, and electrochemical dealloying of Ti6Al4V with a grid diameter of approximately 30 nm obviously promoted HGF formation.

Preparation and evaluation of Indigo Naturalis dry suspension based on powder surface modification / 药学学报

A dry suspension of Indigo Naturalis (IN) based on lactose-IN composite particles was designed by powder modification technology to meet the clinical needs of IN. The contact angle was used as an evaluation index to investigate the effects of the type of modifier lactose, the amount of lactose, and the co-grinding time of lactose and IN on the hydrophilicity of IN. The difference between IN before and after modification was compared through physical properties such as particle size and scanning electron microscope, as well as hydrophilic properties such as surface free energy and multiple light scattering. The optimal process of lactose-IN composite particles is as follows: after lactose is ground alone for 2 minutes, it is co-ground with IN at a ratio of 1∶1 for 6 minutes. The results of the investigation of powder properties show that the particle size d0.9 of IN is reduced from 112.75 μm to 87.30 μm after modification. The BET and Langmuir specific surface areas decreased by 8.661 m2·g-1 and 12.512 m2·g-1, respectively. SEM shows that lactose is attached to the surface of modified IN (MIN); surface element analysis shows that Si, Ca, and Mg elements of MIN are smaller than IN, and O elements are larger. The infrared spectrum shows that the MIN possesses the characteristic peaks of both IN and lactose. Compared MIN with IN, the contact angle and the non-polar surface free energy decreased by 35.1° and 9.975 mJ·m-2, respectively; the polar surface free energy and the surface free energy increased by 36.956 and 26.950 mJ·m-2, respectively. The results of multiple light scattering showed that the light transmittance of MIN was 35% lower than that of IN, and the backscattered light intensity was increased by about 25%. Only one excipient was used to successfully prepare IN dry suspension with good wettability and suspending property, which provided a basis for the development of new preparations of IN.

Research progress of exosome drug loading system / 中国药房

Exosome is a kind of vesicle secreted by a variety of cells with lipid bilayer membrane structure， which has good biocompatibility， high targeting and high stability， and is a natural nanoscale drug carrier with great development potential in drug delivery system. In this paper， exosomes and their properties， exosome drug delivery pathways and methods， the design strategy of engineered exosome drug delivery systems for targeted disease therapy， and the application of exosome drug delivery systems in the treatment of a variety of diseases were reviewed. Exosome drug delivery pathways could be divided into two categories： exogenous and endogenous. Common exosome drug delivery methods included electroporation， co-incubation， and ultrasound. Engineered exosome drug delivery system can further improve drug loading and enhance drug targeting. The main way of engineering is to modify exosome surface through genetic engineering technology， physical modification， chemical modification， etc. Exosome drug delivery system provides a new idea for targeted therapy of arthritis， tumor， brain and other diseases.

Research progress on surface modification of titanium implants by strontium ions / 口腔疾病防治

@#Traditional titanium implants do not completely meet the clinical requirements because they are bioinert. The surface of titanium implants, modified by strontium ions, can enhance osseointegration and reduce peri-implantitis. In this paper, the biological properties of titanium implant surfaces modified by strontium ions were reviewed. Strontium ions can be coated on the implant surface by hydrothermal treatment, electrochemical deposition, phosphate chemical conversion, flame-spraying, supramolecular self-assembly, magnetron sputtering, laser deposition and alkali etching. Implant surfaces modified by strontium ions can not only promote osteogenesis and early osseointegration but also inhibit bacterial growth and reduce postoperative infections. Even better osseointegration and antibacterial effects can be achieved when strontium ions are incorporated with other elements, such as silver, zinc, gallium, and calcium. However, most of the studies on the use of strontium ion-modified titanium implants are animal experiments and in vitro experiments, and the observation time is short compared with the actual service life of the implants. Thus, the conclusions obtained may be different from the actual clinical application, and the long-term effects need to be studied. In addition, the osteogenic effects of various modification methods also need to be compared. Future research can focus on the following points: ① to find efficient modification methods that can be widely used in the clinic; ②to study how to control the concentration of strontium ions near the implant to exert their biological function and reduce their toxic side effects; and ③ to conduct long-term follow-up clinical trials to observe their osteogenic and antibacterial effects.

Characterization and application of several lysis cassettes / 生物工程学报

Lysis is a common functional module in synthetic biology and is widely used in genetic circuit design. Lysis could be achieved by inducing expression of lysis cassettes originated from phages. However, detailed characterization of lysis cassettes hasn't been reported yet. Here, we first adopted arabinose- and rhamnose-inducible systems to develop inducible expression of five lysis cassettes (S105, A52G, C51S S76C, LKD, LUZ) in Escherichia coli Top10. By measuring OD600, we characterized the lysis behavior of strains harboring different lysis cassettes. These strains were harvested at different growth stages, induced with different concentrations of chemical inducers, or contained plasmids with different copy numbers. We found that although all five lysis cassettes could induce bacterial lysis in Top10, lysis behaviors differed a lot at various conditions. We further found that due to the difference in background expression levels between strain Top10 and Pseudomonas aeruginosa PAO1, it was hard to construct inducible lysis systems in strain PAO1. The lysis cassette controlled by rhamnose-inducible system was finally inserted into the chromosome of strain PAO1 to construct lysis strains after careful screen. The results indicated that LUZ and LKD were more effective in strain PAO1 than S105, A52G and C51S S76C. At last, we constructed an engineered bacteria Q16 using an optogenetic module BphS and the lysis cassette LUZ. The engineered strain was capable of adhering to target surface and achieving light-induced lysis by tuning the strength of ribosome binding sites (RBSs), showing great potential in surface modification.

Construction of albumin corona and its application in pharmaceutical preparation / 中国药科大学学报

@#Protein corona is a protein layer that adsorbs on the surface after nonspecific interactions between nanoparticles and plasma proteins.In recent years, studies have shown that modification of specific plasma proteins on the surface of nanoparticles to construct protein corona can prolong the blood half-life of nanoparticles and promote the targeted delivery of nanoparticles, which has attracted widespread attention to the study of drug-carrying systems, among which, albumin corona, the most abundant protein in blood, is the most widely studied.Based on the above, this paper systematically summarized the method of constructing albumin corona and its application in the research on pharmaceutical preparations, in order to provide reference for the construction of albumin corona in the process of drug preparation.

Progress in Application of Heparin Coating in Blood Contact Medical Devices / 中国医疗器械杂志

Blood compatibility is the main restriction of blood-contacting medical devices in clinical application, especially long-term blood-contacting medical devices will stimulate the immune defense mechanism of the host, resulting in thrombosis. Heparin anticoagulant coating links heparin molecules to the surface of medical device product materials, improves the compatibility between the material surface interface and the body, and reduces the host immune defense reactions. This study reviews the structure and biological properties of heparin, the market application status of heparin-coated medical products, the insufficiency and improvement of heparin coating, which can provide a reference for the application research of blood contact medical devices.

Research progress on enhancing biological activity of titanium implants by chairside ultraviolet photofunctionalization / 口腔疾病防治

@#Excellent mechanical properties and biocompatibility resulted in titanium and titanium alloys being widely used in the medical field. However, the biological activity of atitanium surface will gradually fade with increasing exposure time, which affects its final osseointegration. As an effective surface modification method, ultraviolet (UV) photofunctionalization does not change the surface morphology of implants and is a suitable surface treatment for many brands of implants. This article summarizes the research progress on the effect of UV photofunctionalization technology on the characteristics of titanium surfaces, biological activity and implant osseointegration, as well as its current clinical applications. Studies have shown that the superhydrophilicity of the titanium surface and improved biological activity endowed by UV photofunctionalization can accelerate and enhance bone formation, resulting in a higher success rate of implant surgery. Therefore, UV photofunctionalization has great potential for clinical chairside applications.

Advances in interdisciplinary medical and engineering research of intraocular lens surface modifications to prevent posterior capsule opacification / 中南大学学报(医学版)

Posterior capsule opacification (PCO), a common complication after cataract surgery, impacts a patient's long-term visual quality to various degrees. Although a neodymium:yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy is a very effective treatment, it may lead to a serial of complications. Accordingly, the search for simple, safe, and effective methods to prevent PCO has received widespread attention. Various researchers are committed to the interdisciplinary collaboration between medicine and engineering fields, such as functionalizing the surface of the intraocular lens (IOL) via supercritical fluid impregnation, coating the surface of the IOL, high-concentration drug immersion, and application of a drug delivery system, to effectively reduce the incidence and severity of PCO.

Improvement on compactibility of the alcoholic extract of Zingiberis Rhizoma by co-spray drying with HPMC / 中国中药杂志

Aiming to solve the poor compactibility of the alcoholic extract of Zingiberis Rhizoma(ZR), this study explored the feasibility of its physical modification using co-spray drying with a small amount of hydroxypropyl methyl cellulose(HPMC). Based on the univariate analysis, the influence of two independent variables(the HPMC content in the product and the solid content of spray material) on the powder properties and tablet properties of the dried product was investigated by the central composite design. With the tensile strength and disintegration time of the tablets as the evaluation indexes, the optimal prescription was determined as follows: the HPMC content was 15% and the solid content of spray material was 25.6%. The accuracy of the regression model established for predicting tensile strength and disintegration time of tablets was verified, and the results revealed that the measured values were close to the predicted ones with deviations of 0.47% and-8.2%, indicating good prediction and reproducibility of the model. The tensile strength(4.24 MPa) of tablets prepared with the optimal prescription was 3.59 times that(1.18 MPa, far lower than the baseline of 2 MPa for qualified tablets) with the spray-dried powder of the ZR. On the other hand, due to the addition of HPMC, the disintegration time of tablets increased from 7.3 min to 24.6 min. On the whole, this study provided a new strategy to solve the common problem of poor compactibility of raw Chinese medicinal materials, which facilitated the successful preparation of Chinese medicinal tablets with high drug loads.

Preparation of hydrophilic Indigo Naturalis based on polyethylene glycol( PEG) surface film-forming method and evaluation / 中国中药杂志

Polyethylene glycol (PEG) surface film-forming method was used to prepare hydrophilic Indigo Naturalis decoction pieces with stable effect.The preparation process of modified Indigo Naturalis was optimized and its microscopic properties,hydrophilicity,antipyretic efficacy,and safety were systematically evaluated.With equilibrium contact angle as assessment index,the influence of modifier type,modifier dosage,dispersant dosage,and co-grinding time on water solubility of Indigo Naturalis was investigated by single factor test.The results showed that the optimal preparation process was as follows.The 6%PEG6000 is dissolved in 10%anhydrous ethanol solution by sonification and then the mixture is ground with Indigo Naturalis for 2 min.The resultant product is dried on a square tray in an oven at 60℃to remove ethanol and thereby the PEG-modified hydrophilic Indigo Naturalis decoction pieces are yielded.The morphological observation under scanning electron microscope (SEM) indicated that the modified Indigo Naturalis had smoother surface than Indigo Naturalis,and energy spectrometer measurement showed that the nitrogen (N),calcium(Ca),oxygen (O),and silicon (Si) on the surface of modified Indigo Naturalis powder were less than those of Indigo Naturalis powder.Modified Indigo Naturalis had the equilibrium contact angle 18.96°smaller,polar component 22.222 m J·m~(-2)more,and nonpolar component 7.277 m J·m~(-2)smaller than the Indigo Naturalis powder.Multiple light scattering technique was employed to evaluate the dispersion in water and the result demonstrated that the transmittance of Indigo Naturalis and modified Indigo Naturalis was about85%and 75%,respectively,suggesting the higher dispersity of modified Indigo Naturalis.The suspension rate of modified Indigo Naturalis in water was determined by reflux treatment.The result showed that 57%of Indigo Naturalis was not wetted after refluxing for1 h,while the modified Indigo Naturalis was all wetted and dispersed into water.The dissolution of indigo and indirubin of modified Indigo Naturalis increased and the process was more stable.Then,rats were randomized into the blank group,model group,acetaminophen group,Indigo Naturalis group,and hydrophilic Indigo Naturalis group.The temperature changes of rats were observed after administration and the concentration of IL-1βand TNF-αin serum and IL-1βand PGE_2in hypothalamus was measured.The results indicated that the temperature of Indigo Naturalis group and hydrophilic Indigo Naturalis group dropped and the IL-1βlevel of the hydrophilic Indigo Naturalis group decreased (P<0.05) as compared with those in the model group.Thus,both Indigo Naturalis and hydrophilic Indigo Naturalis had antipyretic effect,particularly the hydrophilic Indigo Naturalis.The acute toxicity test of hydrophilic Indigo Naturalis verified that it had no toxicity to rats.In this study,the hydrophilic Indigo Naturalis decoction pieces were prepared with the PEG surface film-forming method,and the antipyretic efficacy and safety were evaluated,which expanded the technological means of powder modification for Chinese medicine and provided a method for clinical use of Chinese medicine.

Interactions between cells and biomaterials in tissue engineering: a review / 生物工程学报

Seed cells, biomaterials and growth factors are three important aspects in tissue engineering. Biomaterials mimic extra cellular matrix in vivo, providing a sound environment for cells to grow and attach, so as to maintain cell viability and function. The physicochemical properties and modification molecules of material surface mediate cell behaviors like cell adhesion, proliferation, migration and differentiation, which in turn affect cellular function and tissue regeneration efficacy. Furthermore, the modification molecules of material surface are the direct contact point for cell adhesion and growth. Therefore, the interactions between cells and surface modification molecules are the key to tissue engineering. This review summarizes the effects of surface modification molecules on cell phenotypes and functions.

Research advances in the effect and utilization of protein corona on the circulation of nanoparticles in vivo / 药学学报

Nanoparticles have better applicability in the detection, treatment of cancer and various difficult diseases, but mononuclear phagocytosis system can seriously shorten the time of nanoparticles in vivo circulation, reduce the drug efficacy. The protein crown formed on the surface of the nanoparticle after entering the body can change its surface properties, interfere with the recognition of phagocytes, and thus affect its circulation time in vivo. This article outlines the general composition and formation process of protein crowns. It also summarizes the influence of the physical and chemical properties of nanoparticles, such as particle size, surface charge, hydrophilicity and surface materials on the formation of protein crowns. The protein crown affects the circulation of nanoparticles in vivo, mainly because the adsorbed opsonic protein promotes cell phagocytosis. Therefore, we also introduce the method of using protein crowns to promote the long circulation of nanoparticles in vivo. By designing appropriate physical and chemical properties, surface modification, and directed design of protein crowns, the adsorption of proteins on the surface of nanoparticles can be reduced. Therefore, it can reduce the clearance of nanoparticles in the mononuclear phagocytic system (mainly the phagocytes of the liver and spleen), and achieve the goal of long circulation of nanoparticles in the body.

Overviewing the Application of ß-Galactosidase "Immobilized on Nanoparticles" in Dairy Industries

Abstract Owing to the excellent catalytic potential, β-galactosidase (EC: 3.2.1.23) has been exploited as an important industrial enzyme for obtaining galactooligosaccharides (GOS) and lactose-free products in dairy industries. Moreover, novel technologies have been implemented in the recent past for preparing and modifying nanoparticles (NPs) for immobilizing therapeutically and industrially important enzymes. Nanoparticles based enzyme immobilization (NBEI) offered more stability and robustness to the enzymes due to their fixed conformation and hence extend their applications in broader areas. A quick overview of the results exhibited greater activity for the enzymes immobilized on NPs as compared to enzyme immobilized on 2-D matrices. Based on these findings, this review was aimed to emphasize the recent development achieved for immobilizing β-galactosidase on NPs with their specific utilization in obtaining dairy products. These studies includes β-galactosidases from various sources that were immobilized on various NPs for hydrolyzing lactose in batch and continuous reactors, and for the production of GOS in biotechnology industries. NBEI of β-galactosidase offered profound stability for transporting substrate and product for enzymatic reactions, apart from cost effective advantage due to reusable nature of immobilized enzyme.

Application of particle design technology in field of traditional Chinese medicine powder / 中国中药杂志

Solid preparations account for more than 50% of traditional Chinese medicines(TCM). TCM powder is an important raw material for solid preparations of TCM. Its powder properties directly affect the quality of solid preparations, and even clinical safety and effectiveness. Particle design technology based on the characteristics of powder in TCM is an important means to improve and enhance the quality of solid preparations. This study summarized the relevant principles, methods, characteristics, classification, equipment, and other elements of particle design technology in recent years, analyzed the difficulties in its application in the field of TCM powder, and proposed the strategies in conjunction with the development of computer data mining. The present study is expected to provide a reference for the suitability of particle design in the field of TCM powder.

Study on the adsorption of inflammatory cytokines and blood compatibility of graphene oxide electrostatic self-assembled polyester material / 中国输血杂志

【Objective】 To investigate the removal efficacy of inflammatory cytokines and blood compatibility of modified PBTNF. 【Methods】 Acrylic acid (AA) was firstly UV-grafted onto the surface of PBTNF to negatively charge the surface of the material. Subsequently, the three positively charged polyelectrolytes, DA, PEI, and CS were respectively electrostatic self-assembled with GO on the surface of PBTNF, forming two layers of film with GO as the outer layer: PBTNF-(DA/GO)2, PBTNF-(PEI/GO)2, PBTNF-(CS/GO)2. 【Results】 Scanning electron microscopy results showed that compared with the PBTNF grafted with AA, the adhesion of particles was observed on the surface of the three modified materials, and the photo shows that the color of the material surface was deepened after electrostatic self-assembly. The results of wettability showed that the surface hydrophilicity was significantly improved, indicating that the electrostatic self-assembled membrane was successfully immobilized on the surface of PBTNF. The removal efficiency (%) of IL-1β for PBTNF-(DA/GO)2, PBTNF-(PEI/GO)2 and PBTNF-(CS/GO)2 were 69.00±7.36 vs -2.35±2.69 vs -1.59±3.26 (P<0.05). The removal efficiency of IL-6 (%) were 40.15±1.86 vs -13.46±5.72 vs -1.21±3.41 (P<0.05). The removal efficiency of IL-8 (%) were 96.90±0.97 vs 17.84±11.74 vs 43.68±17.38 (P<0.05). The removal efficiency of TNF-α (%) was 44.46±2.50 vs 14.90±7.12 vs 20.64±1.22 (P<0.05). Plasma protein adsorption results (total protein, immunoglobulin G, albumin) and red blood cell deformability index showed that there was no statistical difference among the three modified PBTNFs and the control group (P>0.05). Although the red blood cell osmotic fragility (g/L) of the three modified PBTNFs is higher than that of the former: control group vs PBTNF-(DA/GO)2 vs PBTNF-(PEI/GO)2 vs PBTNF-(CS/GO)2: 4.39±0.05 vs 4.62±0.02 vs 4.48±0.03 vs 4.90±0.03 (P<0.05), the hemolysis rate (%) of them were all less than 5%, and PBTNF-(DA/GO)2 performed the lowest hemolysis rate which was (0.03±0.01)% (compared with PBTNF-(PEI/GO)2, P<0.05). The coagulation function test results showed that compared with the control group, the fibrinogen (g/L) of the three modified PBTNFs had no statistical difference (P>0.05); the activated partial thrombo plastin time (S) slightly extended, but all within the normal range of clinical standard; and the prothrombin time (S) of PBTNF-(CS/GO)2 was prolonged(P<0.05). 【Conclusion】 Among the three positively charged polyelectrolytes, including DA, PEI, and CS, PBTNF-(DA/GO)2 performed the best removal rate of inflammatory cytokines, and the blood compatibility evaluation results showed that PBTNF-(DA/GO)2 had no significant effect on red blood cells and coagulation function. Consequently, in the study of inflammatory cytokines adsorption, DA is expected to be the optimal polyelectrolyte assembling with GO for further research.

Improvement on the tableting properties of traditional Chinese medicine extracts by fluid-bed coating and pore forming / 药学学报

This paper aimed to study the effect of combined co-processing of coating and pore forming on the tableting and tablet properties of traditional Chinese medicine (TCM) extracts together with its applicability. Four TCM extracts were co-processed using fluid bed with hydroxypropyl methyl cellulose (HPMC) as coating agent and ammonium bicarbonate (NH4HCO3) as pore-forming agent. Powder properties (such as particle size and size distribution, bulk density, tap density, moisture content) and tablet properties (including tensile strength, compaction ratio, fast elastic stretch, and disintegration time) were measured and compared among the powders. Scanning electron microscopy (SEM) was applied to characterize the surface of particles and tablets. Results showed that the particle size, flowability, and compactibility of the composite particles with HPMC were superior to the parent powders of TCM extracts. These properties of the porous particles with HPMC and NH4HCO3 showed further improvements. In addition, the addition of HPMC prolonged the disintegration time of tablets, whereas the pore-forming effect of NH4HCO3 could shorten the disintegration time. SEM revealed the changes in the morphology of the composite particles and the pores on the surface of the porous particles and tablets. In conclusion, co-processing with HPMC and NH4HCO3 could improve the powder and tablet properties of TCM extract powders, and this method shows certain applicability, which provides a feasible choice for improving the tableting properties of some TCM extract powders.

Research progress on antibacterial properties of porous medical implant materials / 中国修复重建外科杂志

Objective: The antibacterial properties of porous medical implant materials were reviewed to provide guidance for further improvement of new medical implant materials. Methods: The literature related to the antibacterial properties of porous medical implant materials in recent years was consulted, and the classification, characteristics and applications, and antibacterial methods of porous medical implant materials were reviewed. Results: Porous medical implant materials can be classified according to surface pore size, preparation process, degree of degradation in vivo, and material source. It is widely used in the medical field due to its good biocompatibility and biomechanical properties. Nevertheless, the antibacterial properties of porous medical implant materials themselves are not obvious, and their antibacterial properties need to be improved through structural modification, overall modification, and coating modification. Conclusion: At present, coating modification as the mainstream modification method for improving the antibacterial properties of porous medical materials is still a research hotspot. The introduction of new antibacterial substances provides a new perspective for the development of new coated porous medical implant materials, so that the porous medical implant materials have a more reliable antibacterial effect while taking into account biocompatibility.

Polyisobutylene and its thermoplastic elastomers: How to transform from industry to medical treatment / 中国组织工程研究

BACKGROUND: Polyisobutylene and block copolymer and its crosslinked product are a kind of novel thermoplastic elastomer. They have unique properties and excellent biocompatibility, which is a promising medical biomaterial and applied extensively. OBJECTIVE: To review the research progress and applications of polyisobutylene and its thermoplastic elastomers, and to discuss the application prospect of polyisobutylene-based polymers as medical implant materials. METHODS: A computer-based retrieval of PubMed, Web of Science, CNKI and WanFang databases was conducted for the articles about polyisobutylene published from 1958 to 2019. The key words were “polyisobutylene and block copolymer, polyisobutylene and thermoplastic elastomer, polyisobutylene and biomaterials, polyisobutylene and modification, polyisobutylene and medical application” in English and Chinese, respectively. In accordance with the inclusion and exclusion criteria, 65 eligible articles were included for review. RESULTS AND CONCLUSION: Polyisobutylene and block copolymer and its crosslinked products have favorable biocompatibility and stability. By making full use of polyisobutylene-based materials’ advantages, with the combination of other biomaterials and usage of new technology for surface modification, the copolymer will be more competitive in the field of medical implant in the future, including eye implant materials, soft biomaterials and drug delivery systems.

Surface modification of bone tissue engineering implants / 中国组织工程研究

BACKGROUND: Biomedical implants have been widely used in various orthopedic treatments. However, the existing bone implants often have the disadvantages of poor mechanical properties, immune response, microbial infection, poor healing and so on. Different surface modification techniques can effectively make up for these shortcomings. OBJECTIVE: To summarize the surface modification techniques of the current bone tissue engineering implants. METHODS: The first author searched the PubMed, CNKI, and VIP databases to retrieve the articles regarding repair of tuberculous bone defect published during 2000-2009 with the search terms “bone tissue engineering; bone implant; surface modification; coating” in Chinese and English, respectively. The articles published recently or in high-impact journals were included in this study. RESULTS AND CONCLUSION: The surface of bone tissue engineering implants was modified by inorganic and organic components or by changing the surface topography of the implants. This improves the osteogenesis, bone conductivity, bacteriostasis, and biocompatibility of bone implant to different degrees. However, we need to solve some problems before this new implant is applied to the clinic: how to determine the optimal concentration of different surface modification components, maximize bone healing, inhibit bacterial activity, and avoid other adverse reactions; how to avoid foreign body reaction and immune response caused by particles generated by surface abrasion of these bone tissue engineering implants over time; how to incorporate various growth factors, proteins and other biological molecules into the coating without damaging their respective chemical structures and functions; how to guide the release of growth factors and molecules in a coordinated and controllable way.