Proximal femoral bionic nail versus proximal femoral nail antirotation in treatment of femoral intertrochanteric fracture: a comparison of short-term efficacy / 中华创伤骨科杂志

Objective:To compare the short-term effects of proximal femoral bionic nail (PFBN) and proximal femoral nail antirotation (PFNA) in the treatment of intertrochanteric fracture.Methods:Retrospectively analyzed were the data of 56 patients with intertrochanteric fracture of the femur who had been admitted to Department of Orthopedic Trauma, The People's Hospital of Juye County and Trauma Center, Central Hospital Affiliated to The First Medical University of Shandong from August 2020 to April 2022. The patients were divided into 2 even groups according to their internal fixation methods ( n=28). In the PFBN fixation group, there were 12 males and 16 females with an age of (70.4±7.8) years; by AO classification, there were 4 cases of type 31-A1, 16 cases of type 31-A2, and 8 cases of type 31-A3. In the PFNA fixation group, there were 10 males and 18 females with an age of (73.0±8.9) years; by AO classification, there were 2 cases of type 31-A1, 16 cases of type 31-A2, and 10 cases of type 31-A3. The operation time, intraoperative blood loss, fracture reduction, fracture healing time, Harris hip score, and complications were compared between the 2 groups. Results:There was no statistically significant difference between the 2 groups in the preoperative general data, showing comparability ( P>0.05). The follow-up time was (7.3±0.9) months for the PFBN group and (7.4±1.1) months for the PFNA group, showing no significant difference ( P>0.05). There was no significant difference either between the 2 groups in operation time, intraoperative blood loss or quality of fracture reduction ( P>0.05). The PFNA group had significantly shorter fracture healing time [(3.9±0.9) months] than the PFNA group [(4.7±1.1) months], and a significantly higher Harris hip score at the last follow-up [(83.9±4.3) points] than the PFNA group [(81.0±3.4) points] (both P<0.05). Fixation failed in one patient in the PFNA group due to cut-out of the head and neck screws while no complications were observed in the PFBN group. Conclusion:In the treatment of intertrochanteric fracture of the femur, PFBN fixation may result in stronger fixation to effectively avoid cut-out of the head and neck screws, and faster fracture healing and functional recovery of the hip than PFNA fixation.

Research progress in biomimetic nano formulations of biofilms / 中国药科大学学报

@#Biomimetic nano formulations of biofilms have low immunogenicity, high targeting, and good biocompatibility, and can avoid being cleared by the endothelial reticular system, thus with in longer blood circulation time in the body.This article mainly reviews the main types as well as advantages and disadvantages of biomimetic nano formulations of biofilms, including tumor cell membranes, red blood cell membranes, platelet membranes, white blood cell membranes, stem cell membranes, extracellular vesicles (exosomes, microvesicles, and apoptotic bodies), endoplasmic reticulum membranes, and composite biofilms, with also a prospect of the challenges facing biomimetic nano formulations of biofilms and their future development based on their current research status, aiming to provide some insight for further research on biomimetic nano formulations of biofilms.

Highly sensitive H2O2-scavenging nano-bionic system for precise treatment of atherosclerosis

In atherosclerosis, chronic inflammatory processes in local diseased areas may lead to the accumulation of reactive oxygen species (ROS). In this study, we devised a highly sensitive H2O2-scavenging nano-bionic system loaded with probucol (RPP-PU), to treat atherosclerosis more effectively. The RPP material had high sensitivity to H2O2, and the response sensitivity could be reduced from 40 to 10 μmol/L which was close to the lowest concentration of H2O2 levels of the pathological environment. RPP-PU delayed the release and prolonged the duration of PU in vivo. In Apolipoprotein E deficient (ApoE‒/‒) mice, RPP-PU effectively eliminated pathological ROS, reduced the level of lipids and related metabolic enzymes, and significantly decreased the area of vascular plaques and fibers. Our study demonstrated that the H2O2-scavenging nano-bionic system could scavenge the abundant ROS in the atherosclerosis lesion, thereby reducing the oxidative stress for treating atherosclerosis and thus achieve the therapeutic goals with atherosclerosis more desirably.

Effectiveness of proximal femur bionic nail for intertrochanteric fracture in the elderly / 中国修复重建外科杂志

OBJECTIVE@#To evaluate effectiveness of proximal femur bionic nail (PFBN) in treatment of intertrochanteric fractures in the elderly compared to the proximal femoral nail antirotation (PFNA).@*METHODS@#A retrospective analysis was made on 48 geriatric patients with intertrochanteric fractures, who met the selection criteria and were admitted between January 2020 and December 2022. Among them, 24 cases were treated with PFBN fixation after fracture reduction (PFBN group), and 24 cases were treated with PFNA fixation (PFNA group). There was no significant difference in baseline data such as age, gender, cause of injury, side and type of fracture, time from injury to operation, and preoperative mobility score, American Society of Anesthesiologists (ASA) score, Alzheimer's disease degree scoring, self-care ability score, osteoporosis degree (T value), and combined medical diseases between the two groups ( P>0.05). The operation time, intraoperative blood loss, number of blood transfusions, transfusion volume, length of hospital stay, occurrence of complications, weight-bearing time after operation, and postoperative visual analogue scale (VAS) score, walking ability score, mobility score, self-care ability score were recorded and compared between the two groups. And the radiographic assessment of fracture reduction quality and postoperative stability, and fracture healing time were recorded.@*RESULTS@#The operations in both groups were successfully completed. All patients were followed up 6-15 months with an average time of 9.8 months in PFBN group and 9.6 months in PFNA group. The operation time was significantly longer in PFBN group than in PFNA group ( P<0.05), but there was no significant difference in intraoperative blood loss, number of blood transfusions, transfusion volume, length of hospital stay, change in activity ability score, and change in self-care ability score between the two groups ( P>0.05). The weight-bearing time after operation was significantly shorter in PFBN group than in PFNA group ( P<0.05), and the postoperative VAS score and walking ability score were significantly better in PFBN group than in PFNA group ( P<0.05). Radiographic assessment showed no significant difference in fracture reduction scores and postoperative stability scores between the two groups ( P>0.05). All fractures healed and there was no significant difference in fracture healing time between the two groups ( P>0.05). The incidence of complications was significantly lower in PFBN group (16.7%, 4/24) than in PFNA group (45.8%, 11/24) ( P<0.05).@*CONCLUSION@#Compared with PFNA, PFBN in the treatment of elderly intertrochanteric fractures can effectively relieve postoperative pain, shorten bed time, reduce the risk of complications, and facilitate the recovery of patients' hip joint function and walking ability.

Early efficacy comparison of proximal femoral bionic nail and proximal femoral nail anti-rotation in the treatment of intertrochanteric fracture in the elderly / 中华创伤杂志

Objective:To compare the early efficacy of proximal femoral bionic nail (PFBN) and proximal femoral nail anti-rotation (PFNA) in the treatment of intertrochanteric fracture in the elderly.Methods:A retrospective cohort study was conducted to analyze the clinical data of 45 elderly patients with intertrochanteric fracture treated at First Affiliated Hospital of Henan Polytechnic University from March 2020 to December 2021, including 13 males and 32 females; aged 70-96 years [(78.6±7.3)years]. According to the AO classification, there were 10 patients with type 31-A1, 16 type 31-A2 and 19 type 31-A3. There were 20 patients treated with PFBN (PFBN group) and 25 with PFNA (PFNA group). The operation time, intraoperaive blood loss, bone healing time, and time to full weight-bearing were compared between the two groups. The tip-apex distance, distance from tail of lag screw to lateral side of intramedllary nail, proximal femoral length and femur neck-shaft angle were compared between the two groups at day 1 postoperatively and at the last follow-up, and their amount of changes between the two time points were also measured. Harris hip score was evaluated at 3, 6 months postoperatively and at the last follow-up. Complications were observed as well.Results:All patients were followed up for 6-21 months [(14.7±3.6)months]. There were no significant differences in operation time, intraoperative blood loss and bone healing time between the two groups (all P>0.05). The time to full weight-bearing was significantly earlier in PFBN group [(7.9±1.2)weeks] than that in PFNA group [(9.1±0.9)weeks] ( P<0.05). At day 1 postoperatively and at last follow-up, the tip-apex distance was (23.4±1.7)mm and (23.3±1.6)mm in PFBN group ( P>0.05), and was (24.5±2.1)mm and (24.3±2.3)mm in PFNA group ( P>0.05); the distance from tail of lag screw to lateral side of intramedllary nail was (8.1±1.1)mm and (11.8±0.9)mm in PFBN group ( P<0.01), and was (7.7±1.0)mm and (12.6±1.6)mm in PFNA group ( P<0.01); the proximal femoral length was (91.3±1.6)mm and (88.5±2.6)mm in PFBN group ( P<0.01), and was (91.4±2.0)mm and (87.6±2.0)mm in PFNA group ( P<0.01); the femur neck-shaft angle was (127.2±2.9)°and (125.7±3.0)° in PFBN group ( P>0.05), and was (128.5±3.0)° and (127.2±3.2)° in PFNA group ( P>0.05). There were no significant differences in the above indicators between the two groups at day 1 postoperatively and at the last follow-up (all P>0.05). The amount of changes in the tip-apex distance and femur neck-shaft angle were (-0.2±0.1)mm and (-1.6±0.7)° in PFBN group, similar with (-0.2±0.2)mm and (-1.5±1.0)° in PFNA group (all P>0.05). However, the amount of changes in the distance from tail of lag screw to lateral side of intramedllary nail and proximal femoral length were (3.6±1.4)mm and (2.7±1.2)mm in PFBN group, significantly lower than (5.2±1.1)mm and (4.0±1.1)mm in PFNA group (all P<0.01). There were no significant differences in Harris hip score between the two groups at 3, 6 months postoperatively or at the last follow-up (all P>0.05). PFBN group had 1 patient with fracture displacement, 2 with compression screw backup and 2 with thigh pain. PFNA group had 1 patient with fracture displacement and 4 with thigh pain. Conclusion:For elderly patients with intertrochanteric fracture, PFBN provides not only earlier full weight-bearing, but also stronger stability of fracture fixation than PFNA.

Design and function evaluation of 3D-printed hemi-elbow-arthroplastic total humeral prosthesis / 肿瘤研究与临床

Obiective:To investigate the design, the key points of surgery and the outcome of short-term follow-up of hemi-elbow-arthroplastic bionic total humeral prosthesis by using 3D-print.Methods:The clinical data of 8 patients with humerus malignant tumor who underwent total humerus resection and a 3D-printed auxiliary hemi-elbow-arthroplastic total humeral prosthesis replacement from March 2018 to March 2020 at Peking University People's Hospital were retrospectively analyzed. The operative data, oncological outcome, complication profiles of prosthesis and functional status of all 8 patients were also analyzed. There were 3 males and 5 females with a mean age of 5-37 years. Histological diagnosis included 5 cases of osteosarcoma, 2 cases of Ewing's sarcoma and 1 case of chondrosarcoma.Results:The time for production of the prosthesis was (9.8±2.7) d, the operation time was (209±23) min and intraoperative hemorrhage was (569±173) ml. All the prostheses were implanted successfully and no patients experienced intraoperative complications. While 2 patients had postoperative complications, 1 case of temporary palsy of radial nerve and 1 case of local recurrence. LARS artificial ligament or hernia patch was used to reconstruct joint capsule and tendon-ligament attached around the elbow and shoulder joint. The flexion and extension of the elbow was (118±15)° (100-140°) and (11±9)° (0-25°), and the abduction and anteflexion of the shoulder was (28±12)° (15-50°) and (26±9)° (15-40°), respectively. The postoperative Musculoskeletal Tumor Society (MSTS)-93 scale score was (24.1±1.5) scores. The median follow-up time was 17 months (12-32 months), 7 patients had disease-free survival and 1 patient survived with tumor.Conclusions:The novel 3D-printed total humeral prosthesis with hemi-elbow-arthroplasty has a good perioperative safety, which is effective in restoring the function of elbow joint, solving the problem of stress concentration of ulnar marrow lever of total elbow joint prosthesis and lowering long-term wear rate and loosening rate of prosthesis.

Bioaccessibility analysis of active components in Salvia miltiorrhiza / 药学学报

In this study, a method for simultaneous quantitative analysis of 6 salvianolic acids and 4 tanshinones in extracts of Salviae Miltiorrhizae Radix et Rhizoma was established by ultra-high performance liquid chromatography (UHPLC). The semi-biomimetic method was applied to simulate digestion process in vitro, to explore the digestion and transport characters of oral administration through the gastrointestinal tract, and to explain the content ratio changes and bioaccessibility of active ingredients in Salviae Miltiorrhizae Radix et Rhizoma. The results showed that the 10 index components have a good linear relationship in the corresponding concentration range, and the average recovery rate was 91.35% to 105.65%. After simulated digestion in vitro, types of chemical composition in simulated gastric fluid and simulated intestinal fluid digested extracts of Salviae Miltiorrhizae Radix et Rhizoma did not change significantly. While the content ratio of salvianolic acid B and rosmarinic acid decreased, and the content ratio of protocatechuic aldehyde and danshensu increased. In the simulated gastric fluid digestion extract of Salviae Miltiorrhizae Radix et Rhizoma, the order of bioaccessibility was: danshensu (50.19%) > salvianolic acid B (33.44%) > lithospermic acid (27.34%) > salvianolic acid A (21.71%) > rosmarinic acid (12.31%). In the simulated intestinal fluid digestion extract of Salviae Miltiorrhizae Radix et Rhizoma, the order of bioaccessibility was: 15,16-dihydrotanshinone Ⅰ (5.45%) > tanshinone Ⅰ (3.67%) > cryptotanshinone (3.29%) > tanshinone ⅡA (3.01%) > salvianolic acid A (2.39%) > lithospermic acid (1.57%) > salvianolic acid B (1.02%) > danshensu (0.41%) > rosmarinic acid (0.34%). In conclusion, the UHPLC method established in this study can be applied for accurately and sensitively detecting the contents of 6 salvianolic acids and 4 tanshinones in Salviae Miltiorrhizae Radix et Rhizoma. The results of semi-biomimetic extraction showed that not all components were extracted with simulated gastric fluid and simulated intestinal fluid, especially rosmarinic acid and salvianolic acid B. Therefore, in the quality study of Salviae Miltiorrhizae Radix et Rhizoma and its extract, bioavailability should be considered at the same time when select quality markers and determine their content limits.

Frontier hotspots and research progress on 3D bioprinting in organ reconstruction / 器官移植

3D bioprinting is an advanced manufacturing technology that utilizes biomaterials and bioactive components to manufacture artificial tissues and organs. It has been widely applied in multiple medical fields and possesses outstanding advantages in organ reconstruction. In recent years, 3D bioprinted organs have made an array of groundbreaking achievements. Nevertheless, it is still in the exploratory stage of research and development and still has bottleneck problems, which can not be applied in organ transplantation in vivo. In this article, the application of 3D printing technology in medicine, characteristics of 3D bioprinting technology, research hotspots and difficulties in bionic structure, functional reconstruction and immune response of 3D bioprinted organs, and the latest research progress on 3D bioprinting technology were illustrated, and the application prospect of 3D bioprinting technology in the field of organ reconstruction was elucidated, aiming to provide novel ideas for the research and clinical application of organ reconstruction and artificial organ reconstruction, and promote the development of organ transplantation and individualized medicine.

Influence of bionic texture coronary stent on hemodynamics after implantation / 生物医学工程学杂志

To explore the influence of bionic texture coronary stents on hemodynamics, a type of bioabsorbable polylactic acid coronary stents was designed, for which a finite element analysis method was used to carry out simulation analysis on blood flow field after the implantation of bionic texture stents with three different shapes (rectangle, triangle and trapezoid), thus revealing the influence of groove shape and size on hemodynamics, and identifying the optimal solution of bionic texture groove. The results showed that the influence of bionic texture grooves of different shapes and sizes on the lower wall shear stress region had a certain regularity. Specifically, the improvement effect of grooves above 0.06 mm on blood flow characteristics was poor, and the effect of grooves below 0.06 mm was good. Furthermore, the smaller the size is, the better the improvement effect is, and the 0.02 mm triangular groove had the best improvement effect. Based on the results of this study, it is expected that bionic texture stents have provided a new method for reducing in-stent restenosis.

Independent innovation research, development and transformation of precise bionic repair technology for oral prosthesis / 北京大学学报(医学版)

According to the fourth national oral health epidemiological survey report (2018), billions of teeth are lost or missing in China, inducing chewing dysfunction, which is necessary to build physiological function using restorations. Digital technology improves the efficiency and accuracy of oral restoration, with the application of three-dimensional scans, computer-aided design (CAD), computer-aided manufacturing (CAM), bionic material design and so on. However, the basic research and product development of digital technology in China lack international competitiveness, with related products basically relying on imports, including denture 3D design software, 3D oral printers, and digitally processed materials. To overcome these difficulties, from 2001, Yuchun Sun's team, from Peking University School and Hospital of Stomatology, developed a series of studies in artificial intelligence design and precision bionics manufacturing of complex oral prostheses. The research included artificial intelligence design technology for complex oral prostheses, 3D printing systems for oral medicine, biomimetic laminated zirconia materials and innovative application of digital prosthetics in clinical practice. The research from 2001 to 2007 was completed under the guidance of Prof. Peijun Lv and Prof. Yong Wang. Under the support of the National Natural Science Foundation of China, the National Science and Technology Support Program, National High-Tech R & D Program (863 Program) and Beijing Training Project for the Leading Talents in S & T, Yuchun Sun's team published over 200 papers in the relevant field, authorized 49 national invention patents and 1 U.S. invention patent and issued 2 national standards. It also developed 8 kinds of core technology products in digital oral prostheses and 3 kinds of clinical diagnosis and treatment programs, which significantly improved the design efficiency of complex oral prostheses, the fabrication accuracy of metal prostheses and the bionic performance of ceramic materials. Compared with similar international technologies, the program doubled the efficiency of bionic design and manufacturing accuracy and reduced the difficulty of diagnosis and cost of treatment and application by 50%, with the key indicators of those products reaching the international leading level. This program not only helped to realize precision, intelligence and efficiency during prostheses but also provided functional and aesthetic matches for patients after prostheses. The program was rewarded with the First Technical Innovation Prize of the Beijing Science and Technology Awards (2020), Gold Medal of Medical Research Group in the First Medical Science and Technology Innovation Competition of National Health Commission of the People's Republic of China (2020) and Best Creative Award in the First Translational Medical Innovation Competition of Capital (2017). This paper is a review of the current situation of artificial intelligence design and precision bionics manufacturing of complex oral prosthesis.

Application of nano-bionic drug delivery system based on macrophages in tumor therapy / 药学学报

The construction of nano-bionic drug delivery system based on cells or cellular components is a research hotspot of novel drug delivery systems at present. The nano-bionic drug delivery system can integrate the characteristics not only high drug loading and controlled release of nano-carriers, but also good biocompatibility, low immunogenicity and natural targeting from bionic components of cell, and it can also integrate with flexible morphology from living cells. Among them, nano-bionic drug delivery system based on macrophages possesses a good prospect of clinical application because of phagocytic function, inherent tendency, deep penetration ability and potential in cell therapy of macrophages in the treatment of tumors. Based on this, this paper reviews the drug loading strategies of nano-bionic drug delivery system based on macrophages and its application in tumor therapy, so as to provide reference for the development of novel drug delivery systems.

Biomedical applications of bionic untethered micro-nano robots / 生物医学工程学杂志

Bionic untethered micro-nano robots, due to their advantages of small size, low weight, large thrust-to-weight ratio, strong wireless mobility, high flexibility and high sensitivity, have very important application values in the fields of biomedicine, such as disease diagnosis, minimally invasive surgery, targeted therapy, etc. This review article systematically introduced the manufacturing methods and motion control, and discussed the biomedical applications of bionic untethered micro-nano robots. Finally, the article discussed the possible challenges for bionic untethered micro-nano robots in the future. In summary, this review described bionic untethered micro-nano robots and their potential applications in biomedical fields.

In the search of mobile target for acupuncture: why is mast cell? / 中国针灸

Both clinical practice and basic research of acupuncture have pointed out that acupuncture treatment has specific tissue and cellular targets. In addition to the known fixed tissue targets such as nerves and blood vessels, the author analyzes the biological characteristics of other skin resident cells in the skin and concludes that cutaneous mast cells are the most suitable candidate for the cellular target of acupuncture. A hypothesis of the bionic acupuncture is proposed to explain the biological principles by which the innate immunity and healing system respond to acupuncture. The distribution of mast cells in the human skin is characterized by "approaching to the terminals and gathering at the orifices", and the cell density is highly correlated with the density of acupoints and the micro-acupuncture systems. These evidences all support that mast cells are the mobile target cells for acupuncture, which can explain some clinical phenomena and principles of acupuncture, and suggest mast cells as one of the tissue markers for acupoints.

A novel biomimetic micro/nano hierarchical interface of titanium enhances adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal cells / 口腔疾病防治

Objective @#To design a novel biomimetic micro/nano hierarchical interface on endosseous titanium implants and investigate its effect on the biological activity of bone marrow mesenchymal cells.@*Methods@#Electrochemical anodization and spark plasma sintering were used to modify smooth titanium (untreated Ti group) with a microporous trabecular bone-like architecture (micro-Ti group) and TiO2 nanotube architecture (nano-TiO2 group). Additionally, electrochemical anodization was employed to prepare TiO2 nanotubes on microporous trabecular bone-like architectures, which formed a novel biomimetic hierarchical interface (micro/nano-TiO2 group). Four groups of titanium samples were characterized by field emission scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle (CA). Bone marrow mesenchymal cells (BMMCs) were seeded on four groups of titanium samples. Scanning electron microscopy (SEM) was employed to observe cell morphology. Cell proliferation was determined by MTT assay. The expression of focal adhesion proteins (F-actin; vinculin; osteocalcin, OCN; osteopontin, OPN) were observed under a confocal laser scanning microscope (CLSM). The mRNA expression levels of osteogenic factors (runt-related transcription factor 2, RUNX2; osteocalcin, OCN; osteopontin, OPN; collagen I, COL I) were assessed by qRT-PCR.@*Results@# The micro/nano- TiO2 group featured a hydrophilic surface (CA=9° ± 2.1°). The results of the MTT assay indicated that the relative cell proliferation rates for the nano- TiO2 and micro/nano-TiO2 samples were significantly increased compared with those for the untreated-Ti and micro-Ti samples (P＜0.001) after 5-9 days. The ALP results indicated that the micro/nano-TiO2 sample gained the highest value at 14 days. After 72 h of incubation, the expression of osteocalcin (OCN) and osteopontin (OPN) on micro/nano-TiO2 was the strongest. After 24 h incubation, the expression of F-actin on micro/nano-TiO2 was the strongest. In comparison with untreated-Ti and micro-Ti samples,the mRNA expression levels of all the osteogenic factors (runt-related transcription factor 2, RUNX2; osteocalcin, OCN; osteopontin, OPN; Collagen I, COL I) were markedly increased on the nano-TiO2 and micro/nano-TiO2 samples, the mRNA expression levels of collagen I (COL I) were significantly different between the nano-TiO2 and micro/nano-TiO2 samples versus the untreated-Ti and micro-Ti samples (P＜0.001). @* Conclusion@#The novel biomimetic micro/nano hierarchical interface has a positive effect on cell attachment, viability and osteogenic differentiation of bone marrow mesenchymal cells.

Numerical simulation of a self-propelled fish-like swimmer with rigid and flexible caudal fins

Aim: In this paper, numerical simulations were conducted to investigate the swimming performances, hydrodynamics performances and wake structures of a self-propelled swimmer with rigid and flexible caudal fins.Methodology: The kinematics model of the swimmer was constructed using thunniform swimming. Using computational fluid dynamics (CFD) method, the systematic study of swimmer with rigid and flexible caudal fins was carried out. Results: The results showed that the caudal fin flexibility is beneficial to the fast-start of fish but not conducive to the fast cruising of fish. The fish with rigid caudal fin has larger cruising velocity inquasi-steady swimming and smaller forward acceleration in fast-start stage. In addition, the caudal fin flexibility is also beneficial to the heading stability of fish’s self-propelled swimming. The pressure distribution on the fish surface indicates that most of the thrust is generated by the leading-edge region of the caudal fin. The visualization of wake structures showed the existence of the attached leading-edge vortex (LEV) in thunniform swimming. Interpretation: Based on the present simulations, the hydrodynamic performance of tuna during self-propelled swimming was analyzed in detail. Researchers can use these findings to design bionic robot fish with rigid and flexible tails.

Fabrication and evaluation of biomimetic biodegradable tissue-engineered annulus fibrosus scaffold / 中国组织工程研究

BACKGROUND: It is still difficult to construct tissue-engineered anulus fibrosus scaffolds which have bionic structure, suitable biodegradability and good biocompatibility. OBJECTIVE: To fabricate bionic biodegradable scaffolds with polycaprolactone (PCL) and polydioxanone (PDS) and evaluate the feasibility as a tissue-engineered annulus fibrosus scaffold. METHODS: Five groups of scaffolds at different PCL/PDS proportions were prepared by melt spinning technique: PCL, PCL/PDS70/30, PCL/PDS50/50, PCL/PDS30/70, and PDS groups. Scanning electron microscopy was used to observe the structure and measure the fiber diameter and pore size of these prepared scaffolds. The mechanical properties and contact angle of the scaffolds were measured. The in vitro and in vivo biodegradation of the scaffolds were observation by in vitro simulation and subcutaneous implantation. The expression of inflammatory factors interleukin-1β and tumor necrosis factor-α in the biodegraded tissues was detected. Human Wharton’s jelly mesenchymal stem cells were cultured for 7 days. Cell viability and proliferation was determined by live/dead cell staining. This study was approved by the Medical Ethics Committee of Tianjin Hospital, China on March 2, 2016. RESULTS AND CONCLUSION: Scanning electron microscopy results showed that the thickness of the scaffold fibers was uniform and the angle between fibers was 60°. The mechanical properties analysis showed that the tensile and compressive modulus of the PDS group was the lowest, which did not meet the mechanical requirements of the anulus fibrosus; the tensile and compressive modulus in the PCL group was the highest, and those in the PCL/PDS70/30 and PCL/PDS50/50 group were moderate. Hydrophilicity test showed that higher PDS proportion led to better hydrophilicity. Biodegradation test showed that the biodegradation of pure PDS and PCL/PDS30/70 was too fast, that of PCL was too slow, and that of PCL/PDS70/30 and PCL/PDS50/50 was appropriate. Analysis of inflammatory response around the biodegraded tissue showed that higher proportion of PCL in the scaffold resulted in more severe inflammatory response. CCK-8 and live/dead cell staining showed that human Wharton’s jelly mesenchymal stem cells had good proliferative activity and high survival rate in the PCL/PDS70/30, PCL/PDS50/50, and PCL/PDS30/70 groups. These results suggest that scaffolds in the PCL/PDS70/30 and PCL/PDS50/50 groups can simulate the structure of natural annulus fibrosus, have appropriate biodegradability, excellent mechanical properties and good biocompatibility, which make it a suitable candidate for tissue-engineered annulus fibrosus scaffold.

A comparative study on the bone repair effects of two kinds of tissue regeneration membranes / 中国组织工程研究

BACKGROUND: Our previous study confirmed that BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5%BTO (BaTO3, BTO) nanoparticles could significantly promote bone marrow mesenchymal stem cells (BMSCs) adhesion, growth, osteogenic differentiation and repair of bone defects due to its bionic potential. However, for clinical applications, it is not clear whether there is any difference between the bone repair effect of this material as a guide for tissue regeneration and that of the existing clinically non-degradable membrane products. OBJECTIVE: To compare the effects of BTO/P(VDF-TrFE) piezoelectric nano-composite membrane materials with commercial PTFE membrane in repairing critical-sized defects of SD rat skull. METHODS: BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5% BTO nanoparticles was prepared by solution casting method. Scanning electron microscope, atomic force microscope and water contact angle measuring instrument were used to observe the surface morphology, measure the surface roughness and surface hydrophilicity and hydrophobicity of the material. In SD rats (purchased from the Laboratory Animal Center, Beijing University Hospital of Stomatology, China), a 5-mm sized full-thick bone defect was made on both sides of the sagittal suture of the skull. The left bone defect was covered with PTFE membrane (control group). The right bone defect was covered with BTO/P(VDF-TrFE) piezoelectric nano-composite membrane (experimental group). At postoperative 4 and 12 weeks, micro-CT and histological methods were used to evaluate the repair of the skull defect in rats. This study was approved by Animal Ethics Committee, Beijing University Hospital of Stomatology. RESULTS AND CONCLUSION: The piezoelectric nanocomposite membrane had smooth and dense surface and BTO nanoparticles were evenly distributed. PTFE membrane was composed of loose coarse fibers. The piezoelectric nanocomposite membrane had lower surface roughness (P<0.001) and higher hydrophilicity (P<0.001) than PTFE membrane. Micro-CT and histological results showed that at 4 weeks after surgery, new bone formation was found in both groups, but new bone formation was more obvious in the center of the defect in the experimental group than in the control group. At 12 weeks after surgery, bone defects healed in both groups, but the maturity of newly formed bone in the experimental group was greater than that in the control group. These results suggest that BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5%BTO (BaTO3, BTO) nanoparticles can be used as a membrane guiding tissue regeneration.

Research progress in mechanical strength enhancement methods of jaw tissue engineering scaffolds / 口腔疾病防治

@#Bone tissue engineering, as an emerging method for the treatment of jaw defects caused by oral and maxillofacial trauma, inflammation, tumors and other diseases, has been a research hotspot due to its advantages of wide sources of materials, low risk of immune rejection and personalized treatment. However, due to functional activities such as chewing and expression in the oral and maxillofacial regions, the mechanical strength of scaffolds is highly required. A single component of scaffolds can not fully meet the requirements of oral and maxillofacial bone defect repair. In this paper, the methods of strengthening the mechanical strength of jaw bone tissue engineering scaffolds are summarized by summarizing the research on strengthening the mechanical strength of scaffolds in recent years. A review of the literature showed that, composite modification, crosslinking, coating, bionic scaffolding and other new processing methods have been used to enhance the mechanical strength of scaffolds. Among these studies, research on compound modification occurred the earliest. Although this process is simple, other substances have been introduced to increase the number of degradation products, and the compounding ratio needs to be adjusted. The crosslinking method has the risk of cytotoxicity due to the use of crosslinking agents; the coating method does not change the original structure and only changes the surface modification; however, it can be better utilized if the problem of stress concentration between interfaces is solved. Biomimetic scaffolds and microregulatory scaffolds are emerging technologies in recent years that can improve the internal molecular arrangement of materials, thus enhancing mechanical strength. Therefore, on the basis of perfecting the traditional method, future research will focus on new nanoscale materials, bionic scaffolds and new methods for the precise control of scaffold microstructure.

A bionic cerebellar motion control model and its application in arm control / 生物医学工程学杂志

How to realize the control of limb movement and apply it to intelligent robot systems at the level of cerebellar cortical neurons is a hot topic in the fields of artificial intelligence and rehabilitation medicine. At present, the cerebellar model usually used is only for the purpose of controlling the effect, borrowing from the functional mode of the cerebellum, but it ignores the structural characteristics of the cerebellum. In fact, in addition to being used for controlling purposes, the cerebellar model should also have the interpretability of the control process and be able to analyze the consequences of cerebellar lesions. Therefore, it is necessary to establish a bionic cerebellar model which could better express the characteristics of the cerebellum. In this paper, the process that the cerebellum processes external input information and then generates control instructions at the neuron level was explored. By functionally segmenting the cerebellum into homogeneous structures, a novel bionic cerebellar motion control model incorporating all major cell types and connections was established. Simulation experiments and force feedback device control experiments show that the bionic cerebellar motion control model can achieve better control effect than the currently widely used cerebellar model articulation controller, which verifies the effectiveness of the bionic cerebellar motion control model. It has laid the foundation for real brain-like artificial intelligence control.

Anti-arthritic-related metal bioavailability for optimal compatibility ratio of Aconiti Radix Cocta and Paeoniae Radix Alba / 中国中药杂志

Trace metals deficiency or excess are associated with the etiology and pathogenesis of rheumatoid arthritis(RA). Aconiti Radix Cocta(A) and Paeoniae Radix Alba(B) are commonly used together for the treatment of RA. In this study, we aim to determine anti-arthritic-related metal bioavailability in the compatibility of herb A and B for avoiding metal deficiency or excess, and optimize the combination ratio of herb A and B, accordingly. Anti-arthritic-related metal bioaccessibility were evaluated by in vitro simulator of all gastrointestinal tract(including mouth, stomach, small and large intestines), and the roles of gastrointestinal digestive enzymes and intestinal microflora were investigated. Anti-arthritic-related metal bioavailability was assessed by the affinity adsorption with liposomes. The results indicated that compatibility proportion of corresponding herbal plants, gastrointestinal digestion and microbial metabolic, which could affect metal digestion and absorption. The optimal compatibility proportion of 1 A∶1 B is recommended, according to the dose of anti-arthritic-related metal bioavailability, which is often chosen for clinical practice of RA therapy. Thus, anti-arthritic-related metal bioavailability might be the key active substances for RA treatment.