Engineered mesenchymal stem cell-derived extracellular vesicles constitute a versatile platform for targeted drug delivery.

Extracellular vesicles (EVs) are promising therapeutic carriers owing to their ideal size range and intrinsic biocompatibility. However, limited targeting ability has caused major setbacks in the clinical application of EV therapeutics. To overcome this, we genetically engineered natural free streptavidin (SA) on the cellular surface of bone marrow mesenchymal stem cells (BMSCs) and obtained typical EVs from these cells (BMSC-EVs). Biotin-coated gold nanoparticles confirmed the expression of SA on the membrane of EVs, which has a high affinity for biotinylated molecules. Using a squamous cell carcinoma model, we demonstrated that a pH-sensitive fusogenic peptide -modification of BMSC-EVs achieved targetability in the microenvironment of a hypoxic tumor to deliver anti-tumor drugs. Using EGFR+HER2- and EGFR-HER2+ breast cancer models, we demonstrated that anti-EGFR and anti-HER2 modifications of BMSC-EVs were able to specifically deliver drugs to EGFR+ and HER2+ tumors, respectively. Using a collagen-induced arthritis model, we confirmed that anti-IL12/IL23-modified BMSC-EVs specifically accumulated in the arthritic joint and alleviated inflammation. Administration of SA-overexpressing BMSC-EVs has limited immunogenicity and high safety in vivo, suggesting that BMSC-derived EVs are ideal drug delivery vehicle. These representative scenarios of targeting modification suggest that, using different biotinylated molecules, the SA-overexpressing BMSC-EVs could be endowed with different targetabilities, which allows BMSC-EVs to serve as a versatile platform for targeted drug delivery under various situations.

Reconstruction of Buccal-penetrating Defects Using the Double-folded Lateral Arm Free Flap.

The reconstruction of buccal-penetrating defects remains challenging. The present study aims to explore the application value of the lateral arm free flap (LAFF) on the reconstruction of buccal-penetrating defects with the hope of providing a better option for clinical practice. Nineteen patients with this kind of issue posed by either tumor resections or deformities in the craniofacial regions were recruited in this study, and LAFF was employed to reconstruct these defects by double folding and individually designing the flap. All the flaps prepared for these subjects in our study survived, and the postoperative assessment of these subjects receiving LAFF revealed that this approach to managing buccal-penetrating defects is able to achieve satisfactory results in terms of appearance and functional recovery. Therefore, our study suggests that LAFF is 1 of the promising flaps to reconstruct the buccal-penetrating defects.

90 K increased delivery efficiency of extracellular vesicles through mediating internalization.

Using mass spectrometry-based high-throughput proteomics, we identified a membrane protein on extracellular vesicles (EVs), 90 K, which predicts poor overall survival of patients with head and neck cancer. 90 K levels in serum EVs could serve as an independent factor for poor prognosis of patients with head and neck cancer. Pre-treatment of immune competent mice with tumor-derived EVs (TDEs) elicited an immune-suppressive microenvironment for tumor cells, which was regulated by 90 K. The immunosuppressive function of TDE-90 K depends on the presence of myeloid derived suppressor cells (MDSCs) rather than regulatory T cells. The immune regulatory role of TDEs on MDSCs depends on miR-21 which is encapsulated in TDEs. Moreover, 90 K is required for the internalization of TDE cargo though interacting with integrin-ß1 and anti-siglec-9 rather than directly affecting the immune function of MDSCs. 90 K modification of γδT cell-derived EVs (γδTEVs) could increase the delivery efficiency and therapeutic effect of PD-L1 siRNA by γδTEVs. We concluded that as a secreted protein modulating cell-cell and cell-matrix interactions, 90 K can be carried by TDEs to mediate the internalization and delivery of TDEs cargo by recipient cells. This function of 90 K could be utilized to improve the efficiency of EV-based drug delivery.

Multiple congenital granular cell tumours of the maxilla and mandible: a rare case report and review of the literature.

Congenital granular cell tumour (CGCT) is a benign lesion that predominantly arises from the alveolar ridges of neonates, especially the maxilla. However, it's only 10 percent of multiple lesions in all reported cases, in which simultaneously mandibular and maxillary involvements are more extremely rare. For treatments of multiple CGCTs, few standard procedures were reported. In addition to surgical excision, which refers to a preferred method, conservative treatment is an available choice. Here, a case of multiple CGCTs using different therapeutic strategies was reported because of its rarity and innovation. A five-day-old female newborn presented two congenital masses attached to the right mandibular and maxillary alveolar ridge. The size of the mandibular lesion causing difficulty in feeding was 3 cm in diameter and 0.5 cm in the maxilla. Based on different manifestations, surgical excision and conservative treatment were adopted respectively. The mandibular mass was excised while that in the maxilla underwent spontaneous regression. Satisfactory results were achieved for this patient. There was no evidence of recurrence after a 6-month follow-up. Microscopic examination and immunohistochemistry analysis confirmed the diagnosis and differential diagnosis of CGCT and even proposed the possibility of histogenesis from neural crest. Moreover, we reviewed the literature and summarized the characteristics to provide new ideas for the treatment of multiple CGCTs.