Enhancement of BMP-2 and VEGF carried by mineralized collagen for mandibular bone regeneration

Repairing damage in the craniofacial skeleton is challenging.Craniofacial bones require intramembranous ossification to generate tissue-engineered bone grafts via angiogenesis and osteogenesis.Here,we designed a mineralized collagen delivery system for BMP-2 and vascular endothelial growth factor(VEGF)for implantation into animal models of mandibular defects.BMP-2/VEGF were mixed with mineralized collagen which was implanted into the rabbit mandibular.Animals were divided into(i)controls with no growth factors;(ii)BMP-2 alone;or(iii)BMP-2 and VEGF combined.CT and hisomputed tomography and histological staining were performed to assess bone repair.New bone formation was higher in BMP-2 and BMP-2-VEGF groups in which angiogenesis and osteogenesis were enhanced.This highlights the use of mineralized collagen with BMP-2/VEGF as an effective alternative for bone regeneration.

Camrelizumab(SHR-1210) leading to reactive capillary hemangioma in the gingiva: A case report

BACKGROUND Oncologic immunotherapy is attracting attention as an effective strategy for cancer treatment. Currently, there are two kinds of inhibitors: Anti-PD-1 antibodies and anti-PD-L1 antibodies. These inhibitors have shown significant implications in improving the outcomes of certain cancer types in recent years.However, along with its effectiveness, adverse events cannot be ignored. As an anti-PD-1 antibody, camrelizumab(SHR-1210) has some side effects in tumor immunotherapy. The most common adverse event is reactive capillary hemangioma. While it is widely reported to occur in the skin, gingival reactive capillary hemangioma is rarely reported.CASE SUMMARY A 54-year-old man complained of gingival overgrowth on the anterior aspect of the maxilla and mandible for more than 6 mo. He had been placed on SHR-1210 for lung cancer for 7 mo. A gingival mass extending from canine to canine was noted on the lingual surfaces of the mandible. Gingival enlargement was noted in the front teeth. A clinical diagnosis of gingival reactive capillary hemangioma and chronic periodontitis was made. The treatment involved a complex local treatment(repeated local applications of an antibiotic paste, scaling and root planning, and surgery). The excised tissue was sent for histopathological examination, which confirmed the diagnosis of capillary hemangioma. After the operation, most of the gingival enlargement was reduced. At the 2-mo follow-up,it was noted that the gingival overgrowth was immediately reduced after the replacement of the anti-PD-1 agent with an anti-PD-L1 agent.CONCLUSION As the prescription for SHR-1210 has increased considerably in recent years, the occurrence of its possible side effects, including gingival reactive capillary hemangioma, has increased. It is recommended that regular oral examinations be performed before and during the treatment of tumors with SHR-1210.

Probing the intriguing frictional behavior of hydrogels during alternative sliding velocity cycles

Understanding the friction behavior of hydrogels is critical for the long-term stability of hydrogelrelated bioengineering applications.Instead of maintaining a constant sliding velocity,the actual motion of bio-components(e.g.,articular cartilage and cornea)often changes abruptly.Therefore,it is important to study the frictional properties of hydrogels serving under various sliding velocities.In this work,an unexpected low friction regime(friction coefficientμ<10^(-4) at 1.05×10^(-3) rad/s)was observed when the polyacrylamide hydrogel was rotated against a glass substrate under alternative sliding velocity cycles.Interestingly,compared with the friction coefficients under constant sliding velocities,the measuredμdecreased significantly when the sliding velocity changed abruptly from high speeds(e.g.,105 rad/s)to low speeds(e.g.,1.05×10^(-3) rad/s).In addition,μexhibited a downswing trend at low speeds after experiencing more alternative sliding velocity cycles:the measuredμat 1.05 rad/s decreased from 2×10^(-2) to 3×10^(-3) after 10 friction cycles.It is found that the combined effect of hydration film and polymer network deformation determines the lubrication and drag reduction of hydrogels when the sliding velocity changes abruptly.The observed extremely low friction during alternative sliding velocity cycles can be applied to reduce friction at contacted interfaces.This work provides new insights into the fundamental understanding of the lubrication behaviors and mechanisms of hydrogels,with useful implications for the hydration lubrication related engineering applications such as artificial cartilage.