BACKGROUND: Bone-induced protein and its carrier are widely used at present; however, the source is limited, and the preparation is complex. Demineralized dental matrix (DDM) is a natural compound containing many osteoinductional proteins and carriers, thus DDM is an ideal material as the substitute of allogenic bone transplantation.OBJECTIVE: By co-culture of MC-3T3 osteoblast and DDM, to evaluate the biocompatibility of DDM via measuring proliferation and alkaline phosphatase (ALP) activity of osteoblast.DESIGN, TIME AND SETTING: A randomized controlled experiment was performed in Stomatology Hospital of Lanzhou University and Stomatology Hospital of Liwan from November 2007 to May 2009.MATERIALS: DDM was supported by Shenzhen Chuangbo Biological Products Development Co., Ltd.; hydroxyapatite (HAP) was supported by Nanjing Emperor Nano Material Co., Ltd.METHODS: 0.1 g HAP and DDM were added in to a 24-well plate, three wells per samples, and the MC-3T3 osteoblasts were seeded onto the surface of samples. After culturing for 2, 4, and 6 days, the cell proliferation percentage was calculated according to MTT assay. ALP activity was evaluated by the quantitative ALP assay.MAIN OUTCOME MEASURES: The effect of DDM on the proliferation and ALP activity of osteoblasts.RESULTS: The proliferation of osteoblasts in DDM group was obviously higher than that in HAP group. With culture time increasing, the ALP activity of osteoblasts in two groups was all augmented, and DDM group was higher than HAP group. There was significant difference between the two groups (P < 0.05).CONCLUSION: DDM can promote adhesion and proliferation of osteoblasts, and promote osteoblastic growth, displaying a great biocompatibility.

Objective:To investigate the safety and efficacy of proton beam radiation therapy (PBRT) in patients with World Health Organization (WHO) GradeⅠ/Ⅱ meningioma.Methods:Twenty-six patients with intracranial ( n=8, 30.8%) or skull-base ( n=18, 69.2%) meningioma treated with PBRT from May 2015 to October 2018 were analyzed retrospectively. The median age of the cohort was 42 years (range 15-79 years). Eight patients had WHO Grade Ⅰ meningioma, and 9 had WHO Grade Ⅱ meningioma, respectively. Nine patients had clinical (radiological) diagnosis without histology. Seven patients received post-surgical PBRT (2 patients underwent Simpson Ⅰ-Ⅲ resection, 5 patients underwent Simpson Ⅳ-Ⅴ resection); 10 patients were irradiated for local recurrence after initial surgical resection. Results:All patients completed planned PBRT without break, and the median dose was 54 Gray-Equivalent (GyE) (range 50.4-60 GyE, 1.8-2 GyE/daily fraction). With a median follow-up of 22.2 (range 1.6-36.4) months, the 2-year overall survival and progression-free survival rates were both 100%. Grade Ⅰ skin erythema and alopecia were observed in 22 patients and Grade Ⅰ mucositis was observed in 2 patients. No acute of late toxicities of Grade 2 or above was observed.Conclusions:PBRT appeared to be a favorable treatment option for intracranial and skull base meningioma. Treatment-induced adverse effects and early response to PBRT were both highly acceptable. Longer follow-up is needed to evaluate the long-term outcome in terms of disease control, survival, as well as potential late effects.

Objective To evaluate the short-term efficacy and toxicities of intensity-modulated carbon ion radiotherapy (IMCT) for patients with locoregionally recurrent nasopharyngeal carcinoma after intensity-modulated radiotherapy (IMRT).Methods A total of 112 patients with locoregionally recurrent nasopharyngeal carcinoma undergoing salvaging IMCT between May 2015 and February 2018were enrolled in the study.All patients previously received one course of definitive X-ray IMRT.Among them,10 patients (9％) were diagnosed with stage Ⅰ,26 patients (23％) with stage Ⅱ,41 patients (37％) with stage Ⅲ and 35 patients (31％) with stage Ⅳnasopharyngeal carcinoma,respectively.The median age of the cohort was 48 years (range,17-70 years) old.The median dose to the gross tumor volume (GTV) was 60 GyE (range,50-69 GyE).Results With a median follow-up time of 20 months (range,5-45 months),20 patients died and 42 patients developed local recurrence.The 2-year overall survival (OS) and local progression-free survival (LPFS) rates were 85％ and 52％.Both univariate and multivariate analyses demonstrated that stage Ⅳ disease was associated with significantly worse OS.No predictors were found for LPFS.No acute toxicity of grade 3 or higher was observed during reirradiation.Severe (grade 3 or above) late toxicities included xerostomia (n =1),hearing impairment (n =2),temporal lobe injury (n =1) and mucosal necrosis (n =19).Conclusions IMCT is an efficacious and safe treatment for patients with locoregionally recurrent nasopharyngeal carcinoma with acceptable toxicity profile.Long-term follow-up is necessary to further evaluate the long-term efficacy and late toxicities.