Biomedical subjects

Ge Shen

Publications and source records attributed to Ge Shen.

7 recordsLinked to original sources

PubMed2006

Preparation, characterization and cytocompatibility of porous ACP/PLLA composites.

The purpose of this work was to incorporate amorphous calcium phosphate (ACP) into porous poly(L-lactic acid) (PLLA), because ACP is capable of fast phase transformation and morphological change in body fluid, such, a desired pore wall surface within bone tissue engineering scaffolds can be created. A highly porous ACP/PLLA composite was prepared by a thermally induced phase separation technique. The results showed that the composite had an interconnected pore structure with 100 mum macropores and 10 mum micropores, and 91% porosity; 40 nm primary particles of ACP were agglomerated to 3 mum aggregates, and the aggregates were homogeneously distributed in pore walls; These aggregates showed to be in situ transformed into bone-like apatite after 1 h soaking in phosphate buffered saline solution. Human osteoblast-like cell culture showed that the ACP/PLLA composite had better cell adhesion and alkaline phosphotase activity than pure PLLA. This study demonstrates that the ACP/PLLA composite can enhance cytocompatibility and could act as a promising scaffold for bone tissue engineering.

Biocompatible Materials↗

PubMed2005

Preparation and characterization of porous beta-tricalcium phosphate/collagen composites with an integrated structure.

Porous beta-tricalcium phosphate (TCP)/collagen composites with different beta-TCP/collagen weight ratio were prepared. The influences of the preparation conditions on the microstructure of porous composite and the joint status of beta-TCP particles with collagen fibrils were characterized by X-ray diffractometer, scanning electron microscopy and transmission electron microscopy. The results showed: (1) an acid treatment could effectively disassemble collagen fibrils; (2) in the resulting porous composites, beta-TCP particles homogenously existed on the skeleton of the collagen fibril network and bonded tightly to both the fibrils and themselves. The tight bonding formation could be due to the reaction between Ca ions in the particles and carboxyl groups in collagen polypeptide chains and due to the reprecipitation of partially dissolved beta-TCP during synthesis. The tight bonding between beta-TCP particles and collagen fibrils in the composites demonstrated an integrated structure, which was reproducible when beta-TCP/collagen ratio ranged from 2 to 4. Such integrated structure would make significant contributions in reliably tailoring properties of the porous composites by varying beta-TCP content. In addition, the porous composites had large porosity (approximately 95%) and appropriate pore size (approximately 100 microm), showed no negative impact in cytotoxicity assay and complete bone tissue regeneration after 12 weeks in animal test.

Animals↗

PubMed2005

[Relation of dose intensity and efficacy, toxicity in paclitaxel as a single agent for advanced breast cancer].

OBJECTIVE: To evaluate the relation of dose intensity and efficacy, toxicity in advanced breast cancer treated with paclitaxel as a single agent. METHODS: Seventy-one patients with advanced breast cancer received paclitaxel as a single agent with different dose intensities. According to the phase I or phase II trial, the standard dose intensity of paclitaxel was defined as 58.3 mg.(m(2))(-1).week(-1). The dose of paclitaxel was 175 mg/m(2) given every three weeks, ranging 33.3 - 70.3 mg.(m(2))(-1).week(-1) [median delivered dose intensity 58.82 mg.(m(2))(-1).week(-1)]. Efficacy and toxicity was evaluated. RESULTS: The overall response rate in this group of advanced breast cancer was 40.8%. Responses were seen in lungs, soft tissue, bone and liver, with the response rates of 52.0%, 38.0%, 12.5%, 7.7%, respectively. When the relative dose intensity (RDI) was > 1.0, 0.9 - 1.0, < 0.9, the response rates were 44.2%, 47.6%, 0, respectively. The difference between the group (RDI >/= 0.9% - 1.0%) in 7 patients and the group (RDI < 0.9) was significant (P < 0.05). Toxicity was well tolerated, with the efficacy decreased as soon as the RDI had been reduced without embarrassing the toxicity. CONCLUSION: Paclitaxel as a single agent therapy with standard dose intensity is effective and well tolerated by patients with advanced breast cancer.

Adult↗

PubMed2005

[Clinical study of zoledronic acid in the treatment of cancer-induced hypercalcemia].

OBJECTIVE: To investigate the effect and safety of zoledronic acid (Zoledex) in patients with cancer-induced hypercalcemia. METHODS: Seventeen patients with cancer-induced hypercalcemia (corrected blood calcium > 2.70 mmol/L) were treated intravenously by 4 mg zoledex within 15 minutes on the first day. The corrected blood calcium was observed every 4 days in the following 28 days. RESULTS: The response rate was 94.1% (16/17). The mean corrected blood calcium became normal after the first dose of zoledex (P < 0.01). The lowest value was found on the fourteenth day after treatment. The main side effects consisted of fever (29.4%, 5/17), hypocalcemic tetany (11.8%, 2/17) and arythmia (5.9%, 1/17). CONCLUSION: Zoledex is effective and safe in the treatment of patient with cancer-induced hypercalcemia.

Adult↗

PubMed2004

Sol-gel preparation and in vitro test of fluorapatite/hydroxyapatite films.

Fluorapatite/hydroxyapatite (FA/HA) films have been demonstrated to be a good alternative to pure hydroxyapatite (HA) ones in medical applications because of their bioactivity and relatively low solubility. In this study, Ca(NO(3))(2), P(2)O(5), and HPF(6) were used to prepare FA/HA films on Ti6Al4V substrate with the use of a sol-gel method. The F contents in the films could be tailored by adjusting the amount of HPF(6) added. The in vitro evaluation of the films was carried out in both SBF9# solution and TRIS buffer solution. The films with appropriate F contents showed a better ability to induce calcium phosphate deposition on their surfaces than either pure HA film and FA/HA films with even higher F content, as well as smaller dissolution amounts than HA film in TRIS buffer solution. Hence, the FA/HA films obtained in this work integrate both good bioactivity and stability, and could be a better choice for bioactive film on titanium alloys to produce high-quality implants.

Apatites↗

PubMed2004

[Single-agent Xeloda in the treatment of recurrent and metastatic breast cancer].

OBJECTIVE: To evaluate the efficacy and adverse reactions of Xeloda in the treatment of recurrent and metastatic breast cancer. METHODS: This clinical study was designed to treat 69 patients with recurrent and metastatic breast cancer with Xeloda, 2500 mg/m(2)/d, twice daily for 2 weeks followed by a 1-week rest period, repeated every 3 weeks. RESULTS: Sixty-nine patients received Xeloda for more than 1 cycle. The overall response rate (CR + PR) was 16.0%, clinical benefit rate (CR + PR + SD > or = 24 months) was 27.5%, disease control rate (CR + PR + SD) was 75.4%. The median time to failure (TTF) was 3 months (range: 0.7 - 11 months). The median time to progression (TTP) was 2 months (range: 0.7 - 11 months). The median duration of response (CR + PR) was 6 months (range: 4 - 11 months). The most common treatment-related adverse events were hand-foot syndrome (HFS) that occurred in 60.8% (42/69) patients mostly as grade I-II. Fifty-five percent (22/40) of patients who had received high dose preventive Vit B6 developed HFS without grade III; while 69% (20/29) of patients who had not received such treatment did develop HFS including 2 patients with grade III. However, there was not significant difference between the two groups. CONCLUSION: Xeloda is an effective and well tolerated treatment in patients with recurrent and metastatic breast cancer. The symptoms of HFS may be relieved by high dose Vit B6 as prevention.

Adult↗

PubMed2003

[Bone tissue engineering scaffolds].

Bone tissue engineering may provide an alternative to the repairs to skeletal defects resulting from disease, trauma or surgery. Scaffold has played an important role in bone tissue engineering, which functions as the architecture for bone in growth. In this paper, the authors gave a brief introduction about the requirement of bone tissue engineering scaffold, the key of the design of scaffolds and the current research on this subject.

Biodegradation, Environmental↗