Development of a CD39 nanobody and its enhancement to chimeric antigen receptor T cells efficacy against ovarian cancer in preclinical studies.

Rationale: CD39, a key ectonucleotidase that drives adenosine production, acts as a critical immunosuppressive checkpoint in cancer. Although it has shown promise as a therapeutic target, clinical trials are demonstrating the need for more potent targeting approaches. This need is driving innovation towards the development of novel antibodies and the exploration of strategic combinations with a range of immunotherapies. Methods: An anti-CD39 nanobody was screened and tested for its affinity and binding ability using biolayer interferometry, ELISA and flow cytometry. Blocking ability against soluble and membrane-bound CD39 was measured after CD39 blockade. Internalization was detected using immunofluorescence. The reversal of T-cell function by the anti-CD39 antibody was assessed by CFSE-based T-cell proliferation, CD25 expression and IFN-γ secretion. The in vivo function of tumor growth inhibition was further tested in a mouse model and we also tested the phenotype of immune cells after CD39 antibody administration from tumor tissue, draining lymph nodes and peripheral blood. We inserted the antibody sequence into the chimeric antigen receptor (CAR) construct to induce MSLN CAR-T cells to secret the CD39 antibody, and the efficacy was measured in xenograft models of ovarian cancer. Results: We screened human CD39 antibodies using a VHH library and developed a single-epitope anti-CD39 nanobody, named huCD39 mAb, with high affinity and potent binding and blocking ability. The huCD39 mAb was internalized in a time-dependent manner. The in vitro study revealed that the huCD39 mAb was highly effective in enhancing T-cell proliferation and functionality. In vivo, the huCD39 mAb showed significant anti-tumor efficacy in an immunocompetent mouse model. Flow cytometry analysis demonstrated downregulated CD39 expression in immune cells after antibody administration. We also observed increased CD39 expression in ovarian cancer tissue and in activated CAR T cells. Subsequently, we developed a type of MSLN CAR-T cells secreting huCD39 mAb which showed effective eradication or inhibition in ovarian tumor xenografts. Conclusions: A novel huCD39 mAb with strong blocking ability against human CD39 and potent inhibition of tumor growth has been developed. Furthermore, a modified huCD39 mAb-secreting CAR-T cell has been generated, exhibiting superior efficacy against ovarian cancer. This provides a promising strategy for optimizing immunotherapies in ovarian cancer and potentially other malignancies.

One-stage jaw reconstruction and prosthetic rehabilitation with an iliac flap: a case report and literature review.

BACKGROUND: One-stage jaw reconstruction with fibular flap and prosthetic rehabilitation restores bony and dental continuity simultaneously. It was also called as "jaw-in-a-day (JIAD)" technique. However, bone volume and height of fibular flap may be insufficient for dental implant insertion. The provision of a considerable amount of bone makes an iliac flap the ideal choice in these cases. We present the first case report to document the use of one-stage jaw reconstruction and prosthetic rehabilitation with the iliac flap. CASE PRESENTATION: We modified the conventional JIAD workflow to make it suitable for iliac flap. Two cases were presented who both underwent segmental mandibulectomy for ameloblastoma. Virtual surgical planning was performed in all cases. The iliac crest was positioned upward to provide cortical bone for achieving primary stability of dental implants. Similar to the "all-on-4" procedure, the iliac bone was placed 12 to 15 mm below the occlusal plane to create adequate space for the implant-retained prosthesis. Immediate implant-based dental rehabilitation was performed at same stage. The surgery was successful in all cases without any short-term complications. In the first postoperative week, patients were given a liquid diet through a nasal feeding tube. The liquid diet is advised until 1 month after the surgery. Thereafter, a soft diet is recommended. Patients were advised to resume routine mastication and normal diet 3 months after the surgery. Peri-implantitis occurred in one patient, and additional gingival graft was required. Postoperative function and esthetics were satisfactory at the last follow-up visit. CONCLUSIONS: One-stage jaw reconstruction and prosthetic rehabilitation with the iliac flap are safe and useful for restoring postoperative function and esthetics. It should be used in more cases with a longer follow-up in further studies.

A comparison of accuracy among different approaches of static-guided implant placement in patients treated with mandibular reconstruction: A retrospective study.

OBJECTIVE: This study aimed to evaluate the differences in the accuracy of immediate intraoral, immediate extraoral, and delayed dental implant placement with surgical guides (static computer-aided implant surgery) in patients treated with mandibular reconstruction. METHODS: This was a retrospective study. The patients were divided into three groups: immediate intraoral placement (IIO), immediate extraoral placement (IEO), and delayed placement (DEL). Four variables were used to compare the planned and actual implant positions: angular deviation, three-dimensional (3D) deviation at the entry point of the implant, 3D deviation at the apical point of the implant, and depth deviation. RESULTS: The angular deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. The 3D deviation at the entry point was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .01) groups. The 3D deviation at the apical point was significantly higher in the IIO group than in the IEO (p < .01) and DEL (p < .01) groups. The depth deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. There was no statistical difference between the IEO and DEL group in angular and 3D deviation. CONCLUSION: With surgical guides, among the different approaches for implant placement, delayed implant placement remains the most accurate approach for patients treated with mandibular reconstruction.

Occlusal Rehabilitation in a Patient with Oligodontia and Microdontia using Implants and Full-Ceramic Restorations: A Clinical Report.

Oligodontia is the agenesis of six or more permanent teeth, excluding the third molars. Multidisciplinary dental treatments should be performed sequentially due to the restoration requirements for good oral function, aesthetics and self-confidence of patients. In this study, we report a case using dental implants and full-ceramic prostheses to restore the absent and malformed teeth in a patient with agenesis of 18 permanent teeth and with some primary teeth retained. The dental sequential treatments began when she was 16 years old, and she wore removable partial dentures for 4 years with unsatisfying restoration outcome. When she became an adult, dental implants and full-ceramic prostheses were used to restore the absent and malformed teeth. Finally, the patient was very satisfied with the functional and aesthetic outcomes of the prosthetic treatment.

[Ectopic osteogenesis of stromal cell-derived factor 1 combined with simvastatin-loaded collagen scaffold in vivo].

OBJECTIVE: To construct and evaluate a novel tissue-engineered bone composed of murine stromal cell-derived factor 1(mSDF-1), simvastatin (SIM) and collagen scaffold (Bio-Oss®), serving as a cell-homing approach for bone formation. METHODS: In the study, 32 ICR mice were randomly divided into 4 groups,each group including 8 mice. The drug-loaded collagen scaffolds were implanted subcutaneously onto the cranium of each mouse according to the groups: (1) 1:50 (volume ratio) dimethyl sulfoxide (DMSO)/phosphate-buffered saline (PBS) solution + collagen scaffold (blank control group); (2) 10⁻³ mol/L SIM solution + collagen scaffold (SIM group); (3) 200 mg/L mSDF-1 solution + collagen scaffold (mSDF-1 group); and (4) 10® mol/L SIM +200 mg/L mSDF-1 solution + collagen scaffold (SIM + mSDF-1 group). One week after implantation, the mice were treated by injecting the same drug solution mentioned above around the scaffold once a day for two days. The specimens were harvested 6 weeks after implantation and the bone formation was evaluated by soft X-ray analysis, HE staining and immunohistochemical staining. Angiogenesis of each group was checked by calculation of vessels in each tissue section. RESULTS: Six weeks after implantation, the collagen scaffolds were retrieved. The value of gray scale for the SIM+mSDF-1 group [(421 836.5 ± 65 425.7)pixels] was significantly higher than that of the blank control group[(153 345.6 ± 45 222.2) pixels, P<0.01], the SIM group [(158 119.2 ± 100 284.2)pixels, P<0.01], and the mSDF-1 group[(255 529.5 ± 152 142.4)pixels, P<0.05]; HE staining analysis revealed that significant bone formation was achieved in the SIM + mSDF-1 group; The immunohistochemical staining showed the existence of osteopontin and osteocalcin in the SIM + mSDF-1 group; There were more vessels in the SIM+mSDF-1 group[(46 ± 8)vessels/mm²] than in the blank control group [(23 ± 7) vessels/mm2, P<0.01], and the SIM group[(24 ± 6) vessels/mm2, P<0.01]. CONCLUSION: The novel tissue-engineered bone composed of mSDF-1, SIM and collagen scaffolds has the potential to form bone subcutaneously in vivo. It represents a novel method of in vivo bone re-generation without seed cell delivery.

[Correlation between the phenotype and genotype of tooth agenesis patients by tooth agenesis code].

OBJECTIVE: To analyze the correlation between the phenotype and genotype of tooth agenesis using the tooth agenesis code (TAC) and the traditional descriptor for missing teeth. METHODS: Patients with isolated hypodontia caused by PAX9 or MSX1 mutation reported before May 2007 were enrolled. The teeth missing rate and TAC code were recorded. The missing teeth patterns caused by the two mutations were compared. RESULTS: The teeth missing rates in each teeth positions were significantly different between maxillary and mandibular except maxillary central incisor, lateral incisor and mandibular canine, first molar (P<0.05, P<0.001). MSX1 gene mutation often led to the loss of maxillary first premolar, maxillary second premolar, and mandibular second premolar, while PAX9 gene mutation often led to the loss of the first, second, and third molars. The results were similar when analyzed either by TAC code analysis or by traditional descriptor. CONCLUSIONS: PAX9 and MSX1 gene mutation can cause different phenotypes of tooth agenesis. The TAC code can be used in the analysis of the correlation between phenotype and genotype of the missing teeth patients.