A review of emerging bone tissue engineering via PEG conjugated biodegradable amphiphilic copolymers.

Defects in bones can be caused by a plethora of reasons, such as trauma or illness, and in many cases, it poses challenges to the current treatment approaches for bone repair. With increasing demand of bone bioengineering in tissue transplant, there is a need to source for sustainable solutions to induce bone regeneration. Polymeric biomaterials have been identified as a promising approach due to its excellent biocompatibility and controllable biodegradability. Specifically, poly(ethylene glycol) (PEG) is one of the most commonly investigated polymer for use in bio-related application due to its bioinertness and versatility. Furthermore, the hydrophilic nature enables it to be incorporated with hydrophobic but biodegradable polymers like, polylactide (PLA) and polycaprolactone (PCL), to create an amphiphilic polymer. This article reviews the recent synthetic strategies available for the construction of PEG conjugated polymeric system, analysis of PEG influence on the material properties, and provides an overview of its application in bone engineering.

Recent development in cell encapsulations and their therapeutic applications.

Chronic and degenerative diseases are the main causes of death in the aging population worldwide. These diseases are currently maintained using long term administration of conventional drugs which are not curative and reduce the life quality of patients. It is urgent to develop new therapeutic approaches for the treatment of these diseases. Cell therapy that involves the injection of viable cell into patients is a promising therapeutic strategy in chronic and degenerative diseases. However, the survival of injected cells in host tissue is limited due to immunoresponse. Cell encapsulation potentially improves treatment approaches using viable cells and overcome the immuno-rejection following cell transplantation. In this review, we first present the main components and their different functions in the cell encapsulation, including semi permeable membrane, types of cells and matrix. Then, the recently developed technologies and approaches employed to encapsulate cells are summarized and compared in benefits and flaws. More importantly, the insights and significance of the encapsulated cells are also discussed in the application of treating various diseases.

[Treatments of stage-Is testicular mixed germ cell tumors: A report of 3 cases].

OBJECTIVE: To investigate different treatment methods for stage-Is testicular mixed germ cell tumors (TMGCTs). METHODS: We retrospectively analyzed the clinical data about 3'cases of stage-Is TMGCTs (aged 26-39 years) treated in the 175th Hospital of PLA, reviewed relevant literature, and explored the clinical characteristics of TMGCTs. RESULTS: Of the 3 patients, 1 was treated by radical orchiectomy, 1 by radical orchiectomy + retroperitoneal lymph node dissection + BEP chemotherapy scheme, and the other by radical orchiectomy + radiotherapy. The pathological components of TMGCTs were immature teratoma, seminoma, spermatocytoma, chorioepithelioma, embryonal carcinoma, and yolk sac tumor. No recurrence or distant metastasis was found during the 24-month follow-up after surgery. CONCLUSION: The diagnosis of TMGCTs primarily depends on physical examination, ultrasonography, MRI, and measurement of serum tumor markers, while its confirmation necessitates pathological examination, and its treatment is basically radical orchiectomy.

Cementless arthroplasty with a distal femoral shortening for the treatment of Crowe type IV developmental hip dysplasia.

BACKGROUND: Severe developmental dysplasia of the hip is a surgical challenge. The purpose of this study is to describe the cementless arthroplasty with a distal femoral shortening osteotomy for Crowe type IV developmental hip dysplasia and to report the results of this technique. MATERIALS AND METHODS: 12 patients (2 male and 10 female) of Crowe type IV developmental hip dysplasia operated between January 2005 and December 2010 were included in the study. All had undergone cementless arthroplasty with a distal femoral shortening osteotomy. Acetabular cup was placed at the level of the anatomical position in all the hips. The clinical outcomes were assessed and radiographs were reviewed to evaluate treatment effects. RESULTS: The mean followup for the 12 hips was 52 months (range 36-82 months). The mean Harris hip score improved from 41 points (range 28-54) preoperatively to 85 points (range 79-92) at the final followup. The mean length of bone removed was 30 mm (range 25-40 mm). All the osteotomies healed in a mean time of 13 weeks (range 10-16 weeks). There were no neurovascular injuries, pulmonary embolism or no infections. CONCLUSION: Our study suggests that cementless arthroplasty with a distal femoral shortening is a safe and effective procedure for severe developmental dysplasia of the hip.