A shear-thinning, ROS-scavenging hydrogel combined with dental pulp stem cells promotes spinal cord repair by inhibiting ferroptosis.

Spinal cord injury (SCI) is a serious clinical disease. Due to the deformability and fragility of the spinal cord, overly rigid hydrogels cannot be used to treat SCI. Hence, we used TPA and Laponite to develop a hydrogel with shear-thinning ability. This hydrogel exhibits good deformation, allowing it to match the physical properties of the spinal cord; additionally, this hydrogel scavenges ROS well, allowing it to inhibit the lipid peroxidation caused by ferroptosis. According to the in vivo studies, the TPA@Laponite hydrogel could synergistically inhibit ferroptosis by improving vascular function and regulating iron metabolism. In addition, dental pulp stem cells (DPSCs) were introduced into the TPA@Laponite hydrogel to regulate the ratios of excitatory and inhibitory synapses. It was shown that this combination biomaterial effectively reduced muscle spasms and promoted recovery from SCI.

Complete and enduring response in an elderly patient with repeated recurrent gingival squamous cell carcinoma treated by combined toripalimab and single agent chemotherapy: a case report.

Combined immune checkpoint inhibitor with platinum-based doublet chemotherapy brought about significant improvement in overall survival as the first line treatment in metastatic and recurrent head and neck cancer patients. However, in elderly patients with relatively poor performance status, these regimens might not be well tolerated. Therefore, we evaluated the safety and effect of combined immunotherapy and single agent chemotherapy in an elderly patient with recurrent head and neck squamous cell carcinoma. A 78-year-old male patients with a repeatedly recurrent gingival squamous cell carcinoma was admitted in our institute. Previously this patient underwent two consecutive surgical resections of recurrent tumors before the second rapid recurrence that resulted in extended tumor mass and lymph node metastasis. As the patient was in a relatively poor performance status (performance status =2), immunotherapy with PD-1 antibody (Toripalimab) combined with single agent chemotherapy (two cycle with albumin-bound paclitaxel and then six cycles with gemcitabine) was administrated, which led to clinical complete response after 8 cycles of treatment. The patient continued 4 cycles of maintenance immunotherapy with Toripalimab until the outbreak of the coronavirus disease 2019. The treatment was well tolerated and the patient remained free from disease until the last follow up by June 2020, 16 months after the initiation of treatment. The success in this case indicated that the combination of anti-PD-1 antibody and single chemotherapy agent may also be effective as well as safe in elderly patients with recurrent head and neck squamous cell carcinoma.

Hypoxia response element-directed expression of bFGF in dental pulp stem cells improve the hypoxic environment by targeting pericytes in SCI rats.

Cell-based transplantation strategies possess great potential for spinal cord injury (SCI) repair. Basic fibroblast growth factor (bFGF) has been reported to have multiple neuro-promoting effects on developing and adult nervous system of mammals and considered a promising therapy for nerve injury following SCI. Human dental pulp stem cells (DPSCs) are abundant stem cells with low immune rejection, which can be considered for cell replacement therapy. The purpose of this study was to investigate the roles of DPSCs which express bFGF under the regulation of five hypoxia-responsive elements (5HRE) using an adeno-associated virus (AAV-5HRE-bFGF-DPSCs) in SCI repairing model. In this study, DPSCs were revealed to differentiate into CD13+ pericytes and up-regulate N-cadherin expression to promote the re-attachment of CD13+ pericytes to vascular endothelial cells. The re-attachment of CD13+ pericytes to vascular endothelial cells subsequently increased the flow rate of blood in microvessels via the contraction of protuberance. As a result, increased numbers of red blood cells carried more oxygen to the damaged area and the local hypoxia microenvironment in SCI was improved. Thus, this study represents a step forward towards the potential use of AAV-5HRE-bFGF-DPSCs in SCI treatment in clinic.

Oral pH value predicts the incidence of radiotherapy related caries in nasopharyngeal carcinoma patients.

Radiotherapy-related caries is a complication of radiotherapy for nasopharyngeal carcinoma; however, factors influencing the occurrence, accurate prediction of onset, and protective factors of radiotherapy-related caries remain unclear. This study analyzed risk factors, disease predictors, and protective factors for radiotherapy-related caries in nasopharyngeal carcinoma. This prospective study included 138 nasopharyngeal carcinoma patients receiving radical radiotherapy at our hospital during June 2012-December 2016 and were followed up for dental caries. Patients' clinical data on radiotherapy were collected, dynamic monitoring was performed to assess changes in oral pH values, and a questionnaire survey was administered to collect patients' lifestyle habits. Time-dependent cox regression trees, event-free Kaplan-Meier curve, Mann-Whitely U test were used to analysis the results. The median follow-up time was 30 (12-60) months. Radiotherapy-related caries occurred in 28 cases (20.3%). Univariate analyses showed that radiotherapy-related caries was associated with patient's age, oral saliva pH value, green tea consumption, and radiation dose to sublingual glands, but not with the radiation dose to the parotid and submandibular glands. Multivariate analysis showed that oral saliva pH value [hazard ratio (HR) = 0.390, 95% confidence interval = 0.204-0.746] was an independent prognostic factor for radiotherapy-related caries. Patients with oral saliva pH values ≤ 5.3 in the 9th month after radiotherapy represented a significantly higher risks for radiotherapy-related caries (p < 0.001). Green tea consumption was associated with the occurrence of radiotherapy-related caries, and oral saliva pH values could predict the occurrence of radiotherapy-related caries. Limiting radiation doses to sublingual glands can reduce the occurrence of radiotherapy-related caries.