Soybean Lecithin Acts as both Absorption Enhancer and Oily Phase in an Insulin-loaded Emulsion System for Transmucosal Delivery

An insulin-loaded emulsion system （IES） was developed as a hypoglycaemic drug for transmucosal delivery. The selected formulation was a stable oil/water emulsion system. The particles in the emulsion system were distributed evenly, and the particle size ranged from 20 to 260 nm（ average size ： 67.5 nm ）. Soybean lecithin played an important role in the emulsion system due to its abilities of acting as both absorption enhancer for insulin uptake through sublingual mucosa and oily phase for the emulsion system. The laser confocal scanning microscopic（LCSM） study showed that FITC-labelled insulin could penetrate the sublingual mucosa of rabbits, and the phase diagrams of the emulsion system suggested that soybean lecithin could take the place of oily phase to construct a stable emulsion system even if the traditional oil was absent. The applications of soybean lecithin as pharmaceutical biomaterial were extended for the further usage by present studies.

Advances of nanoparticles in transmucosal drug delivery

Transmucosal drug administration represents a potential strategy for enhancing treatment efficacy and reducing side effects by avoiding the first-pass effect into the systemic circulation and delivering therapeutics directly to the target disease site.However,many challenges still remain in its clinical application,including low drug availability and limited retention time in the mucosa.The burgeoning advancement of nanotechnologies offers great potential to overcome the above limitations,leveraging their distinct advantages of high drug-loading capacity and strong permeability.In this review,the latest developments of nanoparticles(NPs)in transmucosal drug delivery as well as their clinical applications are discussed.

Surface modification strategies to reinforce the soft tissue seal at transmucosal region of dental implants

Soft tissue seal around the transmucosal region of dental implants is crucial for shielding oral bacterial invasion and guaranteeing the long-term functioning of implants.Compared with the robust periodontal tissue barrier around a natural tooth,the peri-implant mucosa presents a lower bonding efficiency to the transmucosal region of dental implants,due to physiological structural differences.As such,the weaker soft tissue seal around the transmucosal region can be easily broken by oral pathogens,which may stimulate serious inflammatory responses and lead to the development of peri-implant mucositis.Without timely treatment,the curable peri-implant mucositis would evolve into irreversible peri-implantitis,finally causing the failure of implantation.Herein,this review has summarized current surface modification strategies for the transmucosal region of dental implants with improved soft tissue bonding capacities(e.g.,improving surface wettability,fabricating micro/nano topographies,altering the surface chemical composition and constructing bioactive coatings).Furthermore,the surfaces with advanced soft tissue bonding abilities can be incorporated with antibacterial properties to prevent infections,and/or with immunomodulatory designs to facilitate the establishment of soft tissue seal.Finally,we proposed future research orientations for developing multifunctional surfaces,thus establishing a firm soft tissue seal at the transmucosal region and achieving the long-term predictability of dental implants.

Gastroprotection induced by capsaicin in healthy human subjects

AIM： To evaluate the gastro-protective effect of capsaicin against the ethanol- and indomethacin （IND）-induced gastric mucosal damage in healthy human subjects. METHODS： The effects of small doses （1-8 μg/mL, 100 mL） of capsaicin on the gastric acid secretion basal acid output （BAO） and its electrolyte concentration, gastric transmucosal potential difference （GTPD）, ethanol- （5 mL 300 mL/L i.g.） and IND- （3×25 mg/d） induced gastric mucosal damage were tested in a randomized, prospective study of 84 healthy human subjects. The possible role of desensitization of capsaicin-sensitive afferents was tested by repeated exposures and during a prolonged treatment. RESULTS： Intragastric application of capsaicin decreased the BAO and enhanced “non-parietal” component, GTPD in a dose-dependent manner. The decrease of GTPD evoked by ethanol was inhibited by the capsaicin application, which was reproducible. Gastric microbleeding induced by IND was inhibited by co-administration with capsaicin, but was not influenced by two weeks pretreatment with a daily capsaicin dose of 3×400μg i.g. CONCLUSION： Capsaicin in low concentration range protects against gastric injuries induced by ethanol or IND, which is attributed to stimulation of the sensory nerve endings.

Protective effect of electroacupuncture and moxibustion on gastric mucosal damage and its relation with nitric oxide in rats

INTRODUCTION Gastric mucosal injury is one of the common disorders,there are many reports subjicted to its pathogenesis treatment and prevention.We investigated the protective effect

A clinical perspective on mucoadhesive buccal drug delivery systems

Mucoadhesion can be defined as a state in which two components, of which one is of biological origin, are held together for extended periods of time by the help of interfacial forces. Among the various transmucosal routes, buccal mucosa has excellent accessibility and relatively immobile mucosa, hence suitable for administration of retentive dosage form. The objective of this paper is to review the works done so far in the field of mucoadhe- sire buccal drug delivery systems （MBDDS）, with a clinical perspective. Starting with a brief introduction of the mucoadhesive drug delivery systems, oral mucosa, and the theories of mucoadhesion, this article then proceeds to cover the works done so far in the field of MBDDS, categorizing them on the basis of ailments they are meant to cure. Additionally, we focus on the various patents, recent advancements, and challenges as well as the future prospects for mucoadhesive buccal drug delivery systems.

Worm-like micelles facilitate the intestinal mucus diffusion and drug accumulation for enhancing colorectal cancer therapy

Local delivery of nanoparticles holds promise for colorectal cancer(CRC)therapy.However,the presence of the mucus layer on the epithelium poses a significant challenge to drug delivery,thereby adversely affecting treatment efficiency.It is crucial to develop efficient drug delivery carriers that can effectively overcome mucus barriers to treat colorectal cancer.Herein,we utilized poly(1,4-butadiene)-b-poly(ethylene oxide)polymers to prepare four distinct geometries of polymeric micelles,namely linear micelles(LMs),worm-like micelles(WLMs),large spherical micelles(LSMs),and small spherical micelles(SSMs)to investigate the influence of shape effects on overcoming colonic mucosal barrier.We found that the carriers exhibited diverse shapes while maintaining comparable physicochemical properties.Of these,WLMs had an aspect ratio similar to segmented filamentous bacteria,which exhibited superior mucus penetration ability,leading to prolonged drug release kinetics and faster entry into epithelial cells compared to LSMs.Furthermore,rectally administrated 10-hydroxycamptothecin-loaded WLMs traversed the colorectal mucus in orthotopic CRC nude mice model,penetrated and accumulated within tumor tissue,and effectively aggregated within cancer cells,thereby inducing significantly robust antitumor outcomes in vivo.These findings underscore the significance of shape design in overcoming colonic mucosal absorption barriers,offering a novel approach for the development of drug delivery carriers tailored for effective tumor therapy.

Inhalable metal–organic framework-mediated cuproptosis combined with PD-L1 checkpoint blockade for lung metastasis synergistic immunotherapy

Cuproptosis shows enormous application prospects in lung metastasis treatment.However,the glycolysis,Cu^(+)efflux mechanisms,and insufficient lung drug accumulation severely restrict cuproptosis efficacy.Herein,an inhalable poly(2-(N-oxide-N,N-diethylamino)ethyl methacrylate)(OPDEA)-coated copper-based metal–organic framework encapsulating pyruvate dehydrogenase kinase 1 siRNA(siPDK)is constructed for mediating cuproptosis and subsequently promoting lung metastasis immunotherapy,namely OMP.After inhalation,OMP shows highly efficient lung accumulation and long-term retention,ascribing to the OPDEA-mediated pulmonary mucosa penetration.Within tumor cells,OMP is degraded to release Cu2+under acidic condition,which will be reduced to toxic Cu^(+)to induce cuproptosis under glutathione(GSH)regulation.Meanwhile,siPDK released from OMP inhibits intracellular glycolysis and adenosine-5ʹ-triphosphate(ATP)production,then blocking the Cu^(+)efflux protein ATP7B,thereby rendering tumor cells more sensitive to OMP-mediated cuproptosis.Moreover,OMP-mediated cuproptosis triggers immunogenic cell death(ICD)to promote dendritic cells(DCs)maturation and CD8^(+)T cells infiltration.Notably,OMP-induced cuproptosis up-regulates membrane-associated programmed cell death-ligand 1(PD-L1)expression and induces soluble PD-L1 secretion,and thus synergizes with anti-PD-L1 antibodies(aPD-L1)to reprogram immunosuppressive tumor microenvironment,finally yielding improved immunotherapy efficacy.Overall,OMP may serve as an efficient inhalable nanoplatform and afford preferable efficacy against lung metastasis through inducing cuproptosis and combining with aPD-L1.