Preliminary study of superb microvascular imaging monitoring angiogenesis in tibial transverse transport / 中华骨科杂志

Objective:To investigate the application value of superb microvascular imagingin monitoring angiogenesis in the treatment of chronic ischemic diseases of lower limbs by tibial transverse transport.Methods:From May 2019 to December 2020, 12 patients with ischemic diseases of lower limbs who received tibial transverse transport therapy were retrospectively analyzed, including 7 male patients and 5 female patients, aged 30-86 years, with an average age of 64.0±16.6 years. Among them, there were 10 patients with diabetic foot, with a disease course of 5-30 years (mean 14.4±8.3 years), and 2 patients with arteriosclerosis obliterans. The results of lower extremity superb microvascular imaging before and after treatment were recorded and compared.Results:After treatment, 12 patients were found to have obvious new vessels around the artery of lower extremity, the number of vessels 1-8, the average number of 3.25±2.73. We found that a total of 12 patients 20 inherent lower limb artery collateral established, collateral circulation was found around 12 dorsal metatarsal artery (DMA) in 11 patients, around 3 dorsal pedis artery (DPA) in 2 patients, around 3 anterior tibial artery (ATA) in 2 patients, and around 1 posterior tibial artery (PTA) in 2 patients. The lateral branches were established in ipsilateral lower limbs in 6 patients, contralateral lower limbs in 2 patients, and bilateral lower limbs in 4 patients.Conclusion:The phenomenon of angiogenesis is obvious in the clinical application of tibial transverse transport. Superb microvascular imaging can effectively reflect the degree of promoting the establishment of collateral circulation by tibial transverse transport.

Oral health in China: from vision to action / 国际口腔科学杂志·英文版

Chinese president Xi Jinping made clear at the National Health and Wellness Conference that health is the prerequisite for people's all-around development and a precondition for the sustainable development of China. Oral health is an indispensable component of overall health in humans. However, the long neglect of oral health in overall health agendas has made oral diseases an increasing concern. With this perspective, we described the global challenges of oral diseases, with an emphasis on the challenges faced by China. We also described and analyzed the recently released health policies of the Chinese government, which aim to guide mid-term and long-term oral health promotion in China. More importantly, we called for specific actions to fulfill the larger goal of oral health for the nation. The implementation of primordial prevention efforts against oral diseases, the integration of oral health into the promotion of overall health, and the management of oral diseases in conjunction with other chronic non-communicable diseases with shared risk factors were highly recommended. In addition, we suggested the reform of standard clinical residency training, the development of domestic manufacturing of dental equipment and materials, the revitalization traditional Chinese medicine for the prevention and treatment of oral diseases, and integration of oral health promotion into the Belt and Road Initiative. We look forward to seeing a joint effort from all aspects of the society to fulfill the goal of Healthy China 2030 and ensure the oral health of the nation.

Guangxi cobra venom-derived NGF promotes the osteogenic and therapeutic effects of porous BCP ceramic

Neuro-osteological interactions have an important role in the regulation of bone metabolism and regeneration. Neuropeptides combined with porous biphasic calcium phosphates (BCP) using protein adsorption may contribute to the acceleration of bone formation. In the present study, we investigated the effect of BCP combined with nerve growth factor (NGF) on the growth of osteoblasts in vitro and the combinational therapeutic effect on the repair of calvarial defects in vivo. NGF was separated and purified from Chinese cobra venom using a simplified three-step chromatography method. BCP combined with NGF exerted a potent effect on osteoblast differentiation, as evidenced by enhanced cell proliferation, increased ALP activity and the up-regulated expression of osteogenesis-related genes and proteins. Further, combinational therapy with BCP and NGF improved calvarial regeneration, which was superior to treatment with therapy alone, as observed using imageological and morphological examination and histological and immunohistochemical staining. The results confirmed the effect of neuro-osteological interactions through combinatorial treatment with NGF and BCP to promote osteogenesis and bone formation, which may provide an effective and economical strategy for clinical application.

Inhibitory Effect of Hydroxyapatite Particles with Different Size on Malignant Melanoma A375 Cells: A Preliminary Study / 生物医学工程学杂志

To explore the inhibitory effect of hydroxyapatite (HA) particles with different sizes on malignant melanoma A375 cells in vitro, we synthesized 4 short rod-like HA particles using TIPS. Their mean diameters were 998.0 nm (HA1), 511.0 nm (HA2), 244.0 nm (HA3), and 71.6 nm (HA4), respectively. Malignant melanoma A375 cells were co-cultured with HA particles in vitro. Results showed that HA particles smaller than 511.0 nm in mean diameter could always inhibit proliferation of A375 cells, and nanometer-HA particles (HA4) had the strongest inhibitory effect on A375 cell proliferation and the strongest inducing effect on apoptosis. HA particles were distributed in plasma of A375 cells. The ultrastructure changes of A375 cells were found most significant in nanometer-HA particles (HA4) group. We conclude that particle size is a very important influencing factor on anti-tumor effects of HA and that nanometer-HA particle has the strongest inhibitory effect on tumor cell proliferation.

Progress in experimentaI research on aIIergic asthma treatment with triptoIide / 中国药理学与毒理学杂志

Triptolide(TP)is a diterpenoid epoxide purified from a Chinese herb Tripterygiumwilfordii Hook. f.. lt has been shown to have multiple pharmacological activities,such as anti-tumor,anti-inflammatory,immune-suppressive effects. TP can reduce airway hyperresponsiveness,decrease the proliferation of airway smooth muscle,and produce potential therapeutic effect in airway remodeling. The effect of TP on allergic asthma may be related to its inhibition of maturation of dendritic cells,rebalance of the function of Th1 and Th2,reduction of the secretion of inflammatory factors,and decrease of the infiltration of eosinophils.

A review of research progress on biological effects about nanometer scaffold for bone tissue engineering / 生物医学工程学杂志

Quite a few orthopedics experts have fabricated some novel bone scaffolds with nanotechnology and have carried out some researches on nano-biological effects. The study of the biological effects about nano-biomaterials can facilitate the understanding of the interaction between the biomaterials and the organism, and provide research ideas and direction to construct new biomaterials with physiological function. To better understand the interaction of nano biomaterials with protein, cells and bio-security, this review presents recent advances of biological effects about nano scaffold for bone tissue engineering.

Investigations on preparation and release behavior in vitro of 9-nitro camptothecin encapsulated micelles / 生物医学工程学杂志

9-nitro camptothecin (9-NC) loaded amphiphilic copolymer micelles were prepared with solvent evaporation method. The effects of temperature, distilled water volume, stirring rate, and drug input amount on the size and drug content of micelles were further discussed. As a result, well dispersed spherical micelles with drug content of 4.9 percent and 50 -70 nanometers in diameter were achieved with the following preparation conditions: water bath temperature 60 degrees C , distilled water amount 16 ml, stirring rate 6 500 r/min, and drug input amount 1.2 mg. 9-NC release profiles in vitro illustrated that drug release from micelles included initial burst release and following controlled release. The release rate was decreased with the increase of drug content.

Observation of topography and analysis of surface contamination of titanium implant after roughness treatment / 生物医学工程学杂志

The roughness treatment of dental implant surface could improve the bone bonding and increase the success rate of implant, but the difference of diverse treatments is still unknown. In this study using scanning electron microscopy (SEM), energy disperse spectrometer (EDS) and the test of contact angle, we studied the microstructure, surface contamination and surface energy, and hence conducted a comparative analysis of the following surface roughness treatments: Polished Treatment (PT), Sandblasting with Alumina(SA), Sandblasting with Aluminia and Acid-etched (SAA), Sandblasting with Titanium Acid-etched (STA), Electro-erosion Treatment(ET). The result of SEM showed that the surface displayed irregularities after roughness treatments and that the surface properties of different roughness treatments had some distinctions. SAA and SA had some sharp edges and protrutions; the STA showed a regular pattern like honeycomb, but the ET sample treated by electric erosion exhibited the deeper pores of different sizes and the pores with a perforated secondary structure. The EDS indicated that the surface was contaminated after the treatment with foreign materials; the SA surface had some embedded contaminations even after acid etching. The measurement of water contact angle indicated that the morphology correlated with the surface treatments. These findings suggest that the distinction of surface structure and composition caused by different treatments may result in the disparity in biological behavior of dental implant.

3D finite element analysis of bone stress around distally osseointegrated implant for artificial limb attachment / 生物医学工程学杂志

Using the CT data, we have constructed the finite element models of human femur distally amputated at high-position, middle-position and low-position, along with distally osseointegrated implant under the maximal load during a normal walking cycle. Results of finite element analysis revealed: the maximal stress of implant is produced near the exit of the amputated limb, where the fatigue breakpoint caused by cyclic stress would take place. With the ascending of truncated position, the peri-implant interfacial stress of bone increases. There is severe stress-shielding at the bone-implant interface, and there is concentration of stress at the end of implant and at the 3/4 point of femur, which would lead to bone loss and bone resorption and would shorten the longevity of implant. The results also showed that the curvature of natural bone has notable effect on the stress distribution, which should not be neglected. These data may provide reliable reference for the design and research of osseointegarted artificial limb.

Research development and prospect of calcium phosphate biomaterials with intrinsic osteoinductivity / 生物医学工程学杂志

Calcium phosphates ceramics are frequently used as bone substitute materials in clinics because they are similar to the bone in mineral phase, they are of no antigenicity, and they have good biocompatibility as well as excellent osteoconductivity. The question as to whether calcium phosphate biomaterials possess osteoinductivity has been debated for a long time. Up to now, extensive fundamental studies and clinical application have demonstrated that calcium phosphate ceramics with special structure may induce bone formation in soft tissue. In this paper are reviewed the discovery and confirmation of calcium phosphates ceramics with intrinsic osteoinductivity, the process and mechanism of osteoinduction, and the relationship between osteoinductivity of calcium phosphate materials and animal species, the mesenchymal stem cells related to osteoinduction, the application of osteoinductive biomaterials. The researches directed toward to the osteoinduction of calcium phosphate are prospected.

The effect of gamma-ray irradiation at low temperature on the stability and cytocompatibility of collagen membrane in vitro / 生物医学工程学杂志

Membranes prepared from bovine skin collagen were exposed to 15, 25, 35 KGy gamma-radiation respectively at low temperature. Radiation dose rate of about 22 KGy/h was used. The stability of the membranes was evaluated by measuring resistance of collagen membranes to collagenase digestion. Infrared spectra analyses of collagen films were performed in order to explore possible mechanisms of irradiation modification of collagen membranes. The results revealed that the degree of cross-linking and stability of collagen membranes after gamma-irradiation were improved. The MTT assay and SEM observation of the morphology of L929 mouse fibroblast cells which directly cultured on the collagen membranes were employed to evaluate the cytocompatibility of collagen membranes treated by gamma-ray radiation. In the range of 0 to approximately 25 KGy irradiation dose, no significant difference in cytocompatibility of collagen membranes irradiated by gamma-ray was observed. However, when the irradiation dose was over 25 KGy, the cytocompatibility of collagen membranes was influenced by gamma-radiation to some degree.

In vivo and in vitro studies on anode-oxidized titanium percutaneous implants / 生物医学工程学杂志

In order to solve the problesm in biological sealing of load-bearing percutaneous implants for a fairly long time, we investigated titanium with bioactivated anodic oxidized surface(group A) through the animal tests in vivo and the epithelium cell culture in vitro. Smooth Ti (group B) was used as control. The animal tests results showed that there was no evident difference in the inflammory reaction between the group A implant tissues and the group B implant/tissues. The bioactivated Ti surface could keep the implant not only bonding with the bone firmly but also adhering to the soft tissue closely, thus contributing to the formation of calcium phosphate layer and its micropores. The cell culture results also demonstrated that the microporous surface of group A could clasp and fix the skin. So, it can be concluded that the surface modified method of anode oxidization may be one of the most effective methods to resolve the problem of durable biological sealing.

Comparison between hemolysis percentage measurement and hemiglobincyanide measurement for standardizing the evaluation of hemolytic properties of biomaterials / 生物医学工程学杂志

In this study, two methods--the supernatant hemoglobin spectrophotometry, i.e. hemolysis percentage measurement(according to ISO/TR 7405) and the hemiglobincyanide measurement(according to ISO 10993-4)--were used to assay the hemolytic properties of hydroxyapatite(bioceramics) and collagen (polymer). The results showed that the conclusions drawn from using the two methods were basically consistent, and the latter was more sensitive, stable and comparable. However, some of the procedures in the hemiglobincyanide method were not defined in details. So based on our experiments we have offered some suggestions and improvements, which do not deviate from ISO and ASTM standards, for hiher practicability of usig it in standardizing the evaluation of the hemolytic properties of biomaterials. Hemiglobincyanide measurement is worthy of wider application.

Research of bone bridge-like on plasma sprayed HA coating / 生物医学工程学杂志

Bone formation on hydroxyapatite (HA) coating in the presence of gaps is important for clinical application. Pure Ti and hydroxyapatite coated by plasma sprayed samples were implanted in dog respectively. The implants were surrounded by gaps of 2 mm, and the follow-up period was 12 weeks. Histological examination and histomorphometry revealed that gaps could be bridged by bone provided the hydroxyapatite coating was applied, and that pure Ti implants were surrounded by fibrous tissue with no bone contact at all.

A study of bone-like apatite formation on calcium phosphate ceramics in different kinds of animals in vivo / 生物医学工程学杂志

Bone-like apatite formation on the surface of calcium phosphate ceramics has been believed to be necessary for new bone to grow on the ceramics and to be related to the osteoinductivity of the material. The research of bone-like apatite formation is a great help to understanding the mechanism of osteoinduction. Synthetic porous calcium phosphate ceramics (HA/TCP = 70/30) were implanted intramuscularly in pigs, dogs, rabbits and rats to make a comparative study of the bone-like apatite formation onto the porous HA/TCP ceramics in different animals. Specimens were harvested at 14 days after implantation. Samples were detected for the surface morphology with SEM. The chemical composition of the sample surface after implantation was analyzed with reflection infrared (R-IR). Obvious bone-like apatite formation could be detected in the sections of porous specimens harvested from all animals after 14 days intramuscular implantation. Crystal deposition could be only observed on the surface of the concave regions of the samples collected from dogs, rabbits and rat. On the contrary, evenly distributed flake-shaped crystal could be found on the pore surface and also on the outer surface of the materials implanted in pigs. The morphology of bone-like apatite in pigs was different from that in the others animals. Bone-like apatite was not observed in dense specimen implanted intramuscularly. Bone-like apatite formed faster on specimens implanted in rabbit than that in other animals. This formation sequence is different from the sequence of osteoinductivity of biphasic calcium phosphate ceramics implanted in these animals. The results demonstrated that the formation of bone-like apatite on materials is a prerequisite condition to their osteoinduction but other factors also play important roles in osteoinduction.

Experimental studies on the poly-hydroxybutyrate membrane modified by gamma-radiation and mixed with calcium sulfate / 生物医学工程学杂志

The objective of this study was to learn the property of poly-hydroxybutyrate membrane (PHBm) modified by gamma-radiation and mixture of calcium sulfate, and to explore the possibility of using modified PHBm for guided tissue regeneration (GTR). The PHB was treated by 5 KGy gamma-radiation and mixed with 1/10 calcium sulfate. The modified PHB membrane was prepared by solvent-casting techniques. The mechanical properties and molecular weight of the modified PHBm were tested. Degradability of the modified PHBm was analyzed in vitro in a buffer solution of KH2PO4-Na2HPO4. Biodegradability and biocompatibility of the modified PHBm were inspected 1, 2, 3 and 6 months after the embedding of the modified PHBm into dogs. The morphology was analyzed by scanning electron microscopy (SEM) and molecular weight was tested to evaluate the biodegradability of PHBm. Biocompatibility of the modified PHBm was observed through tissue response by light microscopy. The extension strength and the extension strain at fracture of the modified PHBm were 23.8 MPa and 1.0% respectively. The morphologic observation of the modified PHBm at different terms showed that the modified PHBm was biodegraded gradually in vitro and in vivo. The capsule surrounding the modified PHBm was mainly composed of fibrocytes and few lymphocytes. The longer the time elapsed, the thinner the capsule enveloping the modified PHBm grew. The modified PHBm possesses satisfactory mechanical properties and biocompatibility, and it is biodegradable in vitro and in vivo. The modified PHB membrane could be applied as GTR membrane.

The effects of surface morphology of calcium phosphate ceramics on apatite formation in dynamic SBF / 生物医学工程学杂志

Bone-like apatite formation on the surface of calcium phosphate ceramics has been believed to be the prerequisite of new bone growth on ceramics and to be related to the osteoinductivity of the material. The research of the factors effecting bone-like apatite formation is a great help in understanding the mechanism of osteoinduction. This paper is aimed to a comparative study of in vitro formation of bone-like apatite on the surface of dense and rough calcium phosphate ceramics with SBF flowing at different rates. The results showed that the rough surface was beneficial to the formation of bone-like apatite, and the apatite formed faster in 1.5 SBF than in SBF. Rough surface, namely, larger surface area, increased the dissolution of Ca2+ and HPO4(2-) and higher concentration of Ca2+ and HPO4(2-) ions of SBF and was in turn advantageous to the accumulation of Ca2+, HPO4(2-), PO4(3-) near the ceramic surface. Local supersaturating concentration of Ca2+, HPO4(2-), PO4(3-) near sample surface was essential to nucleation of apatite on the surface of sample.

A study of bone-like apatite formation on porous calcium phosphate ceramics in dynamic SBF / 生物医学工程学杂志

This study aimed at investigating the influence of the flow rate of simulated body fluid (SBF) (2 ml/100 ml.min) of body fluid in skeletal muscle upon the formation of bone-like apatite on porous calcium phosphate ceramics. The in vitro immersion experiment in SBF flowing at normal physiological rate is referred to as dynamic SBF. The results showed that bone-like apatite could only formed in the pores of porous calcium phosphate when SBF flow at physiological rate (2 ml/100 ml.min) of body fluid in skeletal muscle. At the same time, bone-like apatite could form both in the pores and on the surface of the samples if the flowing physiological solution is 1.5 SBF. When the flowing speed of SBF is higher than normal physiological speed (10 ml/100 ml.min), no bone-like apatite could be detected both on the surface and in the pores of the materials. This result is in concordance with animal experiments. The dynamic SBF simulates the biological environment of bone-like apatite formation in body better than static SBF (SBF does not flow). This method is very useful for the research of the mechanism of bonelike apatite formation, which is the key step of bone growth on biomaterials, and can be used as an effective approach to investigate mechanism of the osteoinduction of calcium phosphate in nonosseous tissues in vivo.