New Device for Securing Nasotracheal Intubation Tube During Oral and Maxillofacial Surgery.

Since 2018, we have been using a 3D printer to fabricate a proprietary device for fixing nasotracheal tubes. The aim of this retrospective study was to investigate the impact of this nasotracheal intubation (NTI) fixation device. It has been used in 335 patients undergoing general anesthesia for oral and maxillofacial surgeries. No necrosis or permanent tissue damage was observed, and none of the patients developed complications requiring treatment. No unintentional tube-related incidents such as extubation, dislocation of the tube, or disconnection between the tube and the artificial respiration circuit occurred either. This fixation device offers three advantages: safety, no impediment to surgery, and minimal invasiveness. Of these, safety is the most important. The high degree of immobilization it offers makes it possible to prevent injury to the nasal ala when the tracheal tube is tugged to the cranial side. There is also a high degree of immobilization at the connection site between the tracheal tube and anesthesia circuit, making it possible to prevent disconnection due to intraoperative pressure. In addition, safety during fixation is less likely to differ depending on the degree of proficiency of the individual anesthesiologist. The presence of a groove through which the sampling tube of the capnometer can be passed makes it possible to prevent the problem of flexion of the sampling tube, rendering detection impossible during surgery. Thus, use of this fixation device offers the potential to improve immobilization of the tracheal tube and increase intraoperative safety. However, there remain several problems that need to be addressed with this novel device. Further improvements aimed at enhancing safety are planned, therefore.

Development of cell-penetrating peptide-modified MPEG-PCL diblock copolymeric nanoparticles for systemic gene delivery.

To develop a safe and efficient systemic non-viral gene vector, methoxy poly(ethylene glycol) (MPEG)/poly(epsilon-caprolactone) (PCL) diblock copolymers conjugated with a Tat analog through the ester or disulfide linkage were synthesized and their suitability as a systemic non-viral gene carrier evaluated. The physicochemical properties of the MPEG-PCL diblock copolymers were determined by GPC, (1)H NMR and FT-IR spectroscopy. The particle sizes and in vitro (COS7 and S-180 cells) transfection efficiencies and cytotoxicity were evaluated. Furthermore, the luciferase activity was then determined in various tissues after intravenous injection of MPEG-PCL-SS-Tat/pCMV-Luc complex into mice bearing S-180 cells. The particle sizes of the MPEG-PCL-Tat copolymers with or without pDNA were about 40 and 60nm, respectively. The luciferase activity in COS7 cells transfected with pCMV-Luc with MPEG-PCL-ester-Tat or MPEG-PCL-SS-Tat was higher than that with pDNA only. MPEG-PCL-SS-Tat greatly increased the transfection efficiency compared to MPEG-PCL-ester-Tat in COS7 and S-180 cells. In an in vitro cytotoxicity test MPEG-PCL-SS-Tat did not induce any remarkable cytotoxicity. In an in vivo experiment, the synthesized MPEG-PCL-SS-Tat copolymers promoted the delivery and expression of pDNA into tumor tissue in tumor-bearing mice. In conclusion, this vector might be applicable as a tumor-targeting non-viral systemic gene carrier in the clinical setting.

Local gene expression and immune responses of vaginal DNA vaccination using a needle-free injector.

The vaginal mucosa is the most common site of initiation of virus infections that are transmitted through heterosexual intercourse, including HIV and papillomavirus. Thus, in order to prevent or treat these infections, strong vaginal immunity is required as the first line of defense. In this study, to establish a less invasive, safe, convenient and effective immunization method, we examined the local (skin and vagina) gene transfection efficiency of a non-needle jet injector for daily insulin injection. In the skin experiment, the needle-free injector resulted in a marked increase in marker gene expression, compared to the conventional needle-syringe injection. In addition, intradermal DNA vaccination using the needle-free injector dramatically induced IFN-gamma and antibody systemic responses in mice. Furthermore, we investigated the applicability of the needle-free injector as a vaginal vaccination tool in rabbits. Vaginal gene expression using the needle-free injector was significantly greater than that using needle-syringe injection. Moreover, intravaginal vaccination by the needle-free injector promoted vaginal IgA secretion and IFN-gamma mRNA expression in the blood lymphocytes, to a degree significantly higher than that by needle-syringe injection. In conclusion, local vaginal DNA vaccination using a needle-free jet injector is a promising approach for the prevention and treatment of mucosal infectious diseases.

Effective vaginal DNA delivery with high transfection efficiency is a good system for induction of higher local vaginal immune responses.

OBJECTIVES: To investigate the local vaginal and systemic immune responses of effective vaginal DNA delivery with high transfection efficiency, we determined the effects on Th1-dependent cytokine (interferon-gamma) production in spleen and inguinal lymph node cells and antibody responses of vaginal pDNA immunization with a cell-penetrating peptide, and compared our vaginal immunization with intradermal and intranasal immunizations. METHODS: Mice were immunized by vaginal, nasal or dermal administration of pCMV-OVA with or without peptide carriers, and serum, vaginal fluids, spleen and inguinal cells were harvested. The serum immunoglobulin (Ig)G(2a) and vaginal IgA antibody responses were determined by sandwich enzyme-linked immunosorbent assay (ELISA). The interferon-gamma production from spleen cells or inguinal lymph node cells was determined by an ELISA kit. KEY FINDINGS: The direct vaginal immunization strongly induced IgA in the vaginal fluids and interferon-gamma production in the local lymph node draining from the vagina. In addition, co-vaccination with the peptide carriers elevated these immune responses compared with vaccination with pCMV-OVA alone. Vaginal immunization with high transfection efficiency promoted vaginal IgA production to a significantly greater extent than intradermal or nasal immunization. CONCLUSIONS: These results suggested that direct vaginal DNA vaccines under high transfection conditions induced higher local vaginal antibody than that by intranasal or intradermal administration, and peptide carriers effectively elevated mucosal immune responses. Therefore, this vaginal DNA vaccination method may be expected to be useful in the prevention and treatment methods for vaginal infectious diseases such as HIV infection.