Chenyu Wang

A functional chitosan-based hydrogel as a wound dressing and drug delivery system in the treatment of wound healing

Functional active wound dressings are expected to provide a moist wound environment, offer protection from secondary infections, remove wound exudate and accelerate tissue regeneration, as well as to improve the efficiency of wound healing. Chitosan-based hydrogels are considered as ideal materials for enhancing wound healing owing to their biodegradable, biocompatible, non-toxic, antimicrobial, biologically adhesive, biological activity and hemostatic effects. Chitosan-based hydrogels have been demonstrated to promote wound healing at different wound healing stages, and also can alleviate the factors against wound healing (such as excessive inflammatory and chronic wound infection). The unique biological properties of a chitosan-based hydrogel enable it to serve as both a wound dressing and as a drug delivery system (DDS) to deliver antibacterial agents, growth factors, stem cells and so on, which could further accelerate wound healing. For various kinds of wounds, chitosan-based hydrogels are able to promote the effectiveness of wound healing by modifying or combining with other polymers, and carrying different types of active substances. In this review, we will take a close look at the application of chitosan-based hydrogels in wound dressings and DDS to enhance wound healing.

Novel exploration of 3D printed wrist arthroplasty to solve the severe and complicated bone defect of wrist

Purpose n n n n nAlthough proximal row carpectomy, wrist arthrodesis and even total wrist arthroplasty were developed to treat wrist disease using bone and cartilage of the wrist, severe and complicated bone defects caused by ferocious trauma and bone tumors remain a stubborn problem for surgeons. Development and application of the three-dimensional (3D) printing technology may provide possible solutions. n n n n nDesign/methodology/approach n n n n nComputed tomography (CT) data of three cases with severe bone defects caused by either trauma or bone tumor were collected and converted into three-dimensional models. Prostheses were designed individually according to the residual anatomical structure of the wrist based on the models. Both the models and prostheses were produced using 3D printing technology. A preoperative design was prepared according to the models and prostheses. Then arthroplasty was performed after preoperative simulation with printed models and prostheses. n n n n nFindings n n n n nThe diameter of the stem and radial medullary cavity, the direction and location of the prosthesis, and other components were checked during the preoperative design and simulation process phases. The three cases with 3D printed wrist all regained reconstruction of normal anatomy and part of the function after surgery. The average increasing Cooney score rate of Cases 2 and 3 was 133.34 ± 23.57 per cent, and that of Case 1 reached 85 per cent. The average declining rate of the Gartland and Werley Score in Cases 2 and 3 was 65.21 ± 18.89 per cent, and that of Case 1 dropped to 5 per cent in the last follow-up. The scores indicated that patients experienced pain relief and function regain. In addition, the degree of patient satisfaction improved. n n n n nOriginality/value n n n n n3D printed wrist arthroplasty may provide an effective method for severe and complicated cases without sacrificing other bones. Personal customization can offer better anatomy and function than arthrodesis or other traditional surgical techniques.

Intra-Articular Transplantation of Allogeneic BMMSCs Rehabilitates Cartilage Injury of Antigen-Induced Arthritis.

Apart from the immunosuppressive property, which has been widely investigated in the treatment of various autoimmune diseases, bone marrow mesenchymal stem cells (BMMSCs) also exhibit the chondrogenic capacity. Recently, BMMSCs have attracted more and more attention in the remission of rheumatoid arthritis (RA) and the reconstruction of cartilage injury. In addition to the significant regulatory hurdles of systemic treatment by BMMSCs, the poor inhibitory efficiency on articular inflammatory reaction and the inferior result of preventing the persistent destruction of cartilage were observed. Herein, toward the ovalbumin (OVA)-induced arthritis in rabbits, the in situ transplantation of fibrin gel-encapsulated BMMSCs to osteochondral defect was confirmed to result in the decreased levels of cytokines, such as interleukin-1β, interleukin-6, tumor necrosis factor-α, and anti-OVA antibody, in the serum. What is more, the implantation of BMMSCs also inhibited the proliferation of antigen-specific lymphocytes. Meanwhile, the fibrin gel-encapsulated BMMSCs performed outstanding capacity of cartilage repair, resulted in the remission of local joint inflammatory condition, and prevented further articular cartilage damage. The results demonstrated that the transplantation of BMMSCs in fibrin gel to osteochondral defect under arthritic condition could effectively stimulate BMMSCs to exhibit the immunosuppression and cartilage protection capability, as well as cartilage repair. This study provided a new therapeutic strategy for RA-induced cartilage injury through the local transplantation of BMMSCs.

Hydrogel is Superior to Fibrin Gel as Matrix of Stem Cells in Alleviating Antigen-Induced Arthritis

Recently, therapy with bone marrow mesenchymal stem cells (BMMSCs) has been attempted to relieve rheumatoid arthritis (RA) and reconstruct cartilage injury. However, treatment has been unsuccessful in complete prevention of persistent cartilage destruction and resulted in inferior outcomes of cartilage regeneration. Scaffolds are an important construct in the field of cartilage tissue engineering, but their role in arthritis treatment has not yet been fully examined. Here, we transplanted two types of scaffold-assisted BMMSCs: fibrin gel- and poly(l-lactide-co-glycolide)−poly(ethylene glycol)−poly(l-lactide-co-glycolide) (PLGA−PEG−PLGA) hydrogel-assisted BMMSCs referred as FGB and HGB groups, respectively, into subchondral defects for the treatment of antigen-induced arthritis. The administration of exogenous BMMSCs ameliorated joint swelling and decreased both joint surface temperature and inflammatory cytokine levels in both groups. Immune cell composition of the inflammation of surrounding synovium, protection of adjacent cartilage, and improved cartilage repair were also observed. Overall, the HGB group had a better therapeutic efficacy than the FGB group. In conclusion, local transplantation of BMMSCs in subchondral defects presents a novel approach in inducing RA remission and recovery of RA-induced cartilage injury. To induce these changes, the selection of scaffold for cell support is exceedingly important. Further studies are needed regarding the treatment options of subchondral defects in arthritis based on modified scaffold development, application of defined MSCs sources, combination of pharmacotherapeutics, and the addition of factors that inhibit the processes of RA remission, promote the recovery of RA-induced cartilage injury and the relationship between these factors.

Heat treatment effect on the mechanical properties, roughness and bone ingrowth capacity of 3D printing porous titanium alloy

The weak mechanical strength and biological inertia of Ti–6Al–4V porous titanium alloy limit its clinical application in the field of orthopedics. The present study investigated the influence of different solution temperatures (e.g. 800 °C, 950 °C and 1000 °C) on the mechanical properties, roughness and bone ingrowth capacity of Ti–6Al–4V porous titanium alloy prepared by Electron Beam Melting. It was found that the compressive and shear strength were promoted with the increase of solution temperature because of the transformed crystallinity of Ti–6Al–4V titanium alloy and phase changes from TiAl to TiAl + TiV. In addition, the topological morphology, surface roughness and wettability of the porous titanium alloy scaffolds were improved after heat treatment, and in turn, the adhesion rate and cell proliferation of bone marrow mesenchymal stem cells were enhanced. Compared with the scaffolds before and after heat treatment at 800 °C, the scaffolds heat-treated at 950 °C and 1000 °C achieved better bone ingrowth, extracellular matrix deposition and osseointegration. These findings indicate the great potential of heat treatment in possessing Ti–6Al–4V porous titanium alloy for orthopedic implant.

Pelvic reference selection in patients with unilateral Crowe type IV DDH for measuring leg length inequality

We identified the presence of deformities in the affected pelvis of unilateral Crowe type IV DDH patients, and if present, whether the teardrop and ischial lines were parallel with the sacral base line. We also verified whether the sacral base line provided a better pelvic landmark than the teardrop line for determining leg length inequality (LLI). After leveling the pelvis by using a block to lift the short leg, standard anterior-posterior full-length radiography was performed on 10 patients and 10 healthy volunteers as controls. The ratio of pelvic heights on each side of the pelvis, the angles formed by the sacral base line and the other 2 lines between 2 groups were measured. LLI were measured by sacral base line and teardrop line respectively. The ratio between the pelvic heights was lower in the patient group than in the control group (0.95 versus 0.99). The angles between the teardrop and ischial lines and the sacral base line in the patient group were both greater than in the control group (6.08° versus 0.92° and 7.13° versus 0.97°). LLI measured from the sacral base line was larger than from the teardrop line in the patient group (5.55 cm versus 4.36 cm). There was pelvic asymmetry and the sacral base line was not parallel with the other 2 lines in unilateral Crowe type IV DDH. The leveled sacral base line was perpendicular to the longitudinal axis of the body, and may be a better choice for accurate LLI measurement in this situation.

Additive manufacturing technique-designed metallic porous implants for clinical application in orthopedics

Traditional metallic scaffold prostheses, as vastly applied implants in clinical orthopedic operations, have achieved great success in rebuilding limb function. However, mismatch of bone defects and additional coating requirements limit the long-term survival of traditional prostheses. Recently, additive manufacturing (AM) has opened up unprecedented possibilities for producing complicated structures in prosthesis shapes and microporous surface designs of customized prostheses, which can solve the drawback of traditional prostheses mentioned above. This review presents the most commonly used metallic additive manufacturing techniques, the microporous structure design of metallic scaffolds, and novel applications of customized prostheses in the orthopedic field. Challenges and future perspectives on AM fabricated scaffolds are also summarized.

A rare case report: enlarged iliopsoas cystic solid mass associated with femoral head necrosis induced by heavy alcohol consumption

Rationale: This article presents an unusual case of a large iliopsoas cystic solid mass associated with femoral head necrosis in a patient with heavy alcohol consumption for years. Patient concerns: The patient reported pain and limitation of movement at the right hip for 4 months. A soft tissue mass can be palpated deep in the groin several days after the onset of pain. Diagnoses: The laboratory assessments indicated an inflammatory response of the patient. Imaging was performed on the femoral head and iliopsoas cyst. The pathological feature of the mass was evaluated through biopsy examination. It was found that iliopsoas cystic solid mass is secondary to the femoral head necrosis induced by heavy alcohol consumption. Interventions: The patient underwent elective total hip arthroplasty. The bursa was excised and the anterior hip capsule closure was performed. Outcomes: After the surgery, imaging results showed a well-positioned prosthesis. At 1-year follow-up, the prosthesis was still well-positioned and no signs of recurrence of iliopsoas bursa were found. Lessons: We suggested the performance of elective total hip arthroplasty, bursa excision, and closure of the anterior hip capsule in patients with femoral necrosis and iliopsoas bursitis presented simultaneously.

The ratio of femoral head diameter to pelvic height in the normal hips of a Chinese population.

ObjectiveThe aim of this study was to determine whether the ratio between the femoral head diameter and pelvic height in a Chinese population is the same as that found in Westerners.Materials and methodsStandard pelvic radiography was performed on a group of 187 Chinese adult subjects consisting of 81 males and 106 females with a mean age of 40xa0years (21–68xa0years). Femoral head diameter (vertical distance from the femoral head–neck junction to the highest point of the femoral head) and pelvic height (vertical distance from the highest point of the iliac crest to the edge of the ischial tuberosities) were measured.ResultsThere were significant differences between males and females (pxa0<xa00.001), and between persons of high height versus low height (pxa0=xa00.011) and medium height (pxa0=xa00.039). There were no significant differences between persons of different age (pxa0=xa00.244), body mass index (pxa0=xa00.091), or between persons of low- and medium-height groups (pxa0=xa00.69). The overall mean ratio between the femoral head diameter and pelvic height was 0.215 (0.173–0.249) with a 95xa0% CIxa0=xa00.214–0.217. The mean ratios in males and females were 0.221 (0.194–0.249) and 0.211 (0.173–0.238), respectively.ConclusionThe mean ratio in Chinese population was similar to the reported ratio in a western population (about 1:5). We suggest that Chinese surgeons may be able to use the Crowe classification to classify patients with hip dysplasia.