Mucoadhesive in situ forming gel for oral mucositis pain control

Recombinant Humanized Collagen Type XVII Promotes Oral Ulcer Healing via Anti-Inflammation and Accelerate Tissue Healing

Introduction

Recombinant humanized collagen, as a novel biomaterial, exhibits multiple excellent biological functions, such as inhibition of inflammation, promotion of cell proliferation and vascular proliferation, and promotion of tissue healing. However, there is a lack of conclusive evidence regarding the specific role of recombinant humanized collagen type 17 (rhCol 17) in oral ulcer healing. This study explored whether rhCol 17 could promote the proliferation of human gingival fibroblasts (HGFs) and inhibit its inflammation, and whether it could promote the healing of oral ulcers in rats by inhibiting inflammation and accelerating tissue healing.

Methods

At the cellular level, we investigated the effect of rhCol 17 on the proliferation of (HGFs) by CCK8; HGFs were mixed with lipopolysaccharide (LPS) to investigate the effect of rhCol 17 on HGFs in an inflammatory state. Eighteen adult male Sprague-Dawley rats were randomly distributed into three groups: blank control group, carbomer group (carbomer sprayed only), and rhCol 17 group (carbomer containing rhCol 17 sprayed), 1 time/day. The samples were collected at D3 and D5. At completion, histological staining and PCR were carried out to study its effect on the healing of oral ulcers in rats.

Results

Through cellular experiments, we found that rhCol 17 possesses good biocompatibility and anti-inflammatory properties, and can effectively promote the proliferation and migration of HGFs, as well as significantly reduce the inflammation level of the cells. The animal experimental results showed that rhCol 17 could significantly reduce the inflammation level, promote collagen deposition and angiogenesis at the ulcer site, thus effectively accelerating the healing of oral ulcers in rats.

Conclusion

In summary, the collagen sprays containing rhCol 17 have excellent anti-inflammatory effects and could accelerate tissue healing and are expected to provide a new effective treatment for patients with recurrent oral ulcers.

Formulation optimization and evaluation of oromucosal in situ gel loaded with silver nanoparticles prepared by green biosynthesis

Treating oral diseases remains challenging as API is quickly washed out of the application site by saliva turnover and mouth movements. In situ gels are a class of application forms that present sol-gel transition's ability as a response to stimuli. Their tunable properties are provided using smart polymers responsible for stimuli sensitivity, often providing mucoadhesivity. In this study, antimicrobial in situ gels of thermosensitive and pH-sensitive polymers loaded with silver nanoparticles were prepared and evaluated. The nanoparticles were prepared by green synthesis using Agrimonia eupatoria L. extract. According to the data analysis, the in situ gel with the most promising profile contained 15 % of Pluronic® F-127, 0.25 % of methylcellulose, and 0.1 % of Noveon® AA-1. Pluronic® F-127 and methylcellulose significantly increased the viscosity of in situ gels at 37 °C and shear rates similar to speaking and swallowing. At 20 °C, a behavior close to a Newtonian fluid was observed while being easily injectable (injection force 13.455 ± 1.973 N). The viscosity of the formulation increased with temperature and reached 2962.77 ± 63.37 mPa·s (37 °C). A temperature increase led to increased adhesiveness and rigidity of the formulation. The critical sol-gel transition temperature at physiological pH was 32.65 ± 0.35 °C. 96.77 ± 3.26 % of Ag NPs were released by erosion and dissolution of the gel after 40 min. The determination of MIC showed effect against E. coli and S. aureus (0.0625 mM and 0.5000 mM, respectively). The relative inhibition zone diameter of the in situ gel was 73.32 ± 11.06 % compared to gentamicin sulfate. This work discusses the optimization of the formulation of novel antibacterial in situ gel for oromucosal delivery, analyses the impact of the concentration of excipients on the dependent variables, and suggests appropriate evaluation of the formulation in terms of its indication. This study offers a promising dosage form for local treatment of oral diseases.

Combating multidrug resistance of breast cancer with ginsenoside Rh2-irrigated nano-in-thermogel

The emergence of multidrug resistance (MDR) is the leading cause of mortality in patients with breast cancer. Overexpressed P-glycoprotein (P-gp) that can pump out chemotherapeutics from multidrug-resistant cancer cells is the main cause of chemotherapy failure. P-gp inhibitors are hence increasingly used to sensitize chemotherapy to breast cancer with MDR by reducing the efflux of drugs. However, representative P-gp inhibitors usually have severe side effects and the effect of their release behavior on chemotherapy are neglected in current studies. We constructed a nano-in-thermogel delivery system with the sequential release of ginsenoside Rh2 (GRh2) and a chemotherapeutic drug in the tumor microenvironment as a drug compounding "reservoir" to combat MDR in breast cancer. Briefly, paclitaxel (PTX) and GRh2 were encapsulated in solid lipid nanoparticles (SLNs) and dispersed in a poloxamer-based thermogel (SLNs-Gel). GRh2 was used as an innovative and safe P-gp inhibitor to lower P-gp expression and cellular adenosine triphosphate context, thereby sensitizing PTX-resistant breast cancer cells (MCF-7/PTX) to PTX. Pharmacodynamic and in vivo safety studies confirmed that intratumoral injection of SLNs-Gel significantly suppressed the proliferation of PTX-resistant breast cancer and alleviated the PTX-induced hematotoxicity. The GRh2-irrigated nano-in-thermogel delivery system shows great potential in combating multidrug-resistant cancer.

A magnetic multi-layer soft robot for on-demand targeted adhesion

Magnetic soft robots have shown great potential for biomedical applications due to their high shape reconfigurability, motion agility, and multi-functionality in physiological environments. Magnetic soft robots with multi-layer structures can enhance the loading capacity and function complexity for targeted delivery. However, the interactions between soft entities have yet to be fully investigated, and thus the assembly of magnetic soft robots with on-demand motion modes from multiple film-like layers is still challenging. Herein, we model and tailor the magnetic interaction between soft film-like layers with distinct in-plane structures, and then realize multi-layer soft robots that are capable of performing agile motions and targeted adhesion. Each layer of the robot consists of a soft magnetic substrate and an adhesive film. The mechanical properties and adhesion performance of the adhesive films are systematically characterized. The robot is capable of performing two locomotion modes, i.e., translational motion and tumbling motion, and also the on-demand separation with one side layer adhered to tissues. Simulation results are presented, which have a good qualitative agreement with the experimental results. The feasibility of using the robot to perform multi-target adhesion in a stomach is validated in both ex-vivo and in-vivo experiments.

Preparation of Tamsulosin Hydrochloride-Loaded Mucoadhesive In Situ Gelling Polymeric Formulation for Nasal Delivery in Geriatrics

This study aimed to prepare tamsulosin hydrochloride (HCl)-loaded in situ gelling formulation by using hydroxypropyl methylcellulose (HPMC), gellan gum, poloxamer 188, and benzalkonium chloride. Physicochemical evaluation of formulations included determination of pH, viscosity, gelation time, gel strength, drug content, and sterility. In silico study was performed to analyze interactions between polymers, drug, and mucin glycoprotein. In vitro degradation time, drug release, ex vivo mucoadhesion time, permeation, in vivo pharmacokinetics, and stability studies were performed to assess the formulation. Formulations were transparent and displayed acceptable physicochemical attributes. Tamsulosin HCl and polymers interacted via non-covalent interactions. HPMC formed hydrogen bonds, hydrophobic and van der Waals interactions with mucin protein while the drug formed hydrogen bonds only. Gel formulation degraded in simulated nasal fluid within 24 h. In situ gelling formulation showed 83.8 ± 1.7% drug release and remained adhered to the mucosa for 24.5 ± 1 h. A higher (~ 1.85 times) drug permeation was recorded through mucosa within 6 h by in situ gelling formulation when compared to control counterparts (aqueous solution of drug and in situ gelling formulation without poloxamer 188). Nasal administration of tamsulosin HCl by using in situ gelling formulation led to a ~ 3.3 and ~ 3.5 times, respectively, higher Cmax (maximum plasma concentration) and AUCtotal (total area under the curve) than the orally administered aqueous solution. Relative bioavailability of drug delivered by nasal in situ gelling formulation was 3.5 times the oral counterpart. These results indicated that the prepared in situ gelling formulation can act as a promising candidate for systemic administration of tamsulosin HCl.

Research progress related to thermosensitive hydrogel dressings in wound healing: a review

Wound healing is a dynamic and complex process in which the microenvironment at the wound site plays an important role. As a common material for wound healing, dressings accelerate wound healing and prevent external wound infections. Hydrogels have become a hot topic in wound-dressing research because of their high water content, good biocompatibility, and adjustable physical and chemical properties. Intelligent hydrogel dressings have attracted considerable attention because of their excellent environmental responsiveness. As smart polymer hydrogels, thermosensitive hydrogels can respond to small temperature changes in the environment, and their special properties make them superior to other hydrogels. This review mainly focuses on the research progress in thermosensitive intelligent hydrogel dressings for wound healing. Polymers suitable for hydrogel formation and the appropriate molecular design of the hydrogel network to achieve thermosensitive hydrogel properties are discussed, followed by the application of thermosensitive hydrogels as wound dressings. We also discuss the future perspectives of thermosensitive hydrogels as wound dressings and provide systematic theoretical support for wound healing.

Formulation and Evaluation of Prednisolone Sodium Metazoate-Loaded Mucoadhesive Quatsomal Gel for Local Treatment of Recurrent Aphthous Ulcers: Optimization, In Vitro, Ex Vivo, and In Vivo Studies

This study aims to formulate a buccal mucoadhesive gel containing prednisolone sodium metazoate-loaded quatsomes for efficient localized therapy of recurrent aphthous ulcers. Quatsomes were prepared using a varied concentration of quaternary ammonium surfactants (QAS) and cholesterol (CHO). A 2³ factorial design was conducted to address the impact of independent variables QAS type (X₁), QAS to CHO molar ratio (X₂), and sonication time (X₃). The dependent variables were particle size (PS; Y₁), polydispersity index (PDI; Y₂), zeta potential (ZP; Y₃), entrapment efficiency percent (EE%; Y₄) and percent of drug released after 6 h (Q6%: Y₅). Then, the selected quatsomes formula was incorporated into different gel bases to prepare an optimized mucoadhesive gel to be evaluated via in vivo study. The PS of the developed quatsomes ranged from 69.47 ± 0.41 to 113.28 ± 0.79 nm, the PDI from 0.207 ± 0.004 to 0.328 ± 0.004, ZP from 45.15 ± 0.19 to 68.1 ± 0.54 mV, EE% from 79.62 ± 1.44 to 98.60% ± 1.22 and Q6% from 58.39 ± 1.75 to 94.42% ± 2.15. The quatsomal mucoadhesive gel showed rapid recovery of ulcers, which was confirmed by the histological study and the evaluation of inflammatory biomarkers. These results assured the capability of the developed quatsomal mucoadhesive gel to be a promising formulation for treating buccal diseases.

Mucoadhesive drug delivery systems: a promising noninvasive approach to bioavailability enhancement. Part II: formulation considerations

INTRODUCTION

Mucoadhesive drug delivery systems (MDDS) are specifically designed to interact and bind to the mucosal layer of the epithelium for localized, prolonged, and/or targeted drug delivery. Over the past 4 decades, several dosage forms have been developed for localized as well as systemic drug delivery at different anatomical sites.

AREAS COVERED

The objective of this review is to provide a detailed understanding of the different aspects of MDDS. Part II describes the origin and evolution of MDDS, followed by a discussion of the properties of mucoadhesive polymers. Finally, a synopsis of the different commercial aspects of MDDS, recent advances in the development of MDDS for biologics and COVID-19 as well as future perspectives are provided.

EXPERT OPINION

A review of the past reports and recent advances reveal MDDS as highly versatile, biocompatible, and noninvasive drug delivery systems. The rise in the number of approved biologics, the introduction of newer highly efficient thiomers, as well as the recent advances in the field of nanotechnology have led to several excellent applications of MDDS, which are predicted to grow significantly in the future.

Bacterial cellulose adhesive patches designed for soft mucosal interfaces

The wet environment in the oral cavity is challenging for topical disease management approaches. The compromised material properties leading to weak adhesion and short retention (<8 h) in such environment result in frequent reapplication of the therapeutics. Composites of bacterial cellulose (BC) and carbene-based bioadhesives attempt to address these shortcomings. Previous designs comprised of aqueous formulations. The current design, for the first time, presents dry, shelf-stable cellulose patches for convenient ready-to-use application. The dry patches simultaneously remove tissue surface hydration while retaining carbene-based photocuring and offers on-demand adhesion. The dry patch prototypes are optimized by controlling BC/adhesive mole ratios and dehydration technique. The adhesion strength is higher than commercial denture adhesives on soft mucosal tissues. The structural integrity is maintained for a minimum of 7 days in aqueous environment. The patches act as selective nanoporous barrier against bacteria while allowing permeation of proteins. The results support the application of BC-based adhesive patches as a flexible platform for wound dressings, drug depots, or combination thereof.

Mendelian randomization study on the causal effects of omega-3 fatty acids on rheumatoid arthritis

OBJECTIVES

To resolve the ongoing debate on the role of plasma omega-3 fatty acids in rheumatoid arthritis (RA), we attempted to identify the association between omega-3 intake and the risk of RA.

METHODS

We analyzed data from the largest genome-wide association study (GWAS) for omega-3 fatty acids (N = 114,999 of European ancestry) and RA (14,361 cases and 43,923 controls of European ancestry). Mendelian randomization-egger_intercept, MR-PRESSO, and Cochran's Q test were used to determine pleiotropy and heterogeneity. Egger, weighted median, inverse variance weighted (IVW), simple mode, and weighted mode were used to evaluate the causal association of plasma omega-3 levels on RA.

RESULTS

We found no significant pleiotropy, heterogeneity, and bias among the omega-3 genetic instrumental variables (IVs) in RA GWAS datasets. MR analysis demonstrated that as omega-3 levels genetically increased, the risk of MS increased using MR-egger (Beta = 0.137, p = 0.037; OR = 1.146, 95% CI: [1.014, 1.296]), weighted median (Beta = 0.162, p = 0.001; OR = 1.176, 95% CI: [1.070, 1.292]), IVW (Beta = 0.102, p = 0.025; OR = 1.108, 95% CI: [1.013, 1.211]), simple mode (Beta = 0.219, p = 0.149; OR = 1.245, 95% CI: [0.931, 1.665]), and weighted mode (Beta = 0.146, p = 0.006; OR = 1.157, 95% CI: [1.051, 1.274]).

CONCLUSIONS

Our analysis suggested a causal association between genetically increased plasma omega-3 levels and the increased risk of RA in populations with European ancestry. Thus, to reduce the risk of RA, those of European descent should reduce omega-3 intake. Key Points • No significant pleiotropy or heterogeneity among the omega-3 genetic IVs in RA GWAS datasets. • Genetically increased plasma omega-3 levels enhanced the risk of RA in European lineages.

Fibrillated bacterial cellulose liquid carbene bioadhesives for mimicking and bonding oral cavity surfaces

Topical treatments for oral wounds and infections exhibit weak adhesion to wet surfaces which results in short retention duration (6-8 hours), frequent dosing requirement and patient incompatibility. To address these limitations, aqueous composites made of fibrillated bacterial cellulose and photoactive bioadhesives are designed for soft epithelial surfaces. The aqueous composites crosslink upon photocuring within a minute and exhibit a transition from viscous to elastic adhesive hydrogels. The light-cured composites have shear moduli mimicking oral mucosa and other soft tissues. The tunable adhesion strength ranges from 3 to 35 kPa on hydrated tissue-mimicking surfaces (collagen film). The results support the application of bacterial cellulose hydrogel systems for potential treatment of mucosal wounds.

Hydroxypropylmethylcellulose as a film and hydrogel carrier for ACP nanoprecursors to deliver biomimetic mineralization

Demineralization of hard tooth tissues leads to dental caries, which cause health problems and economic burdens throughout the world. A biomimetic mineralization strategy is expected to reverse early dental caries. Commercially available anti-carious mineralizing products lead to inconclusive clinical results because they cannot continuously replenish the required calcium and phosphate resources. Herein, we prepared a mineralizing film consisting of hydroxypropylmethylcellulose (HPMC) and polyaspartic acid-stabilized amorphous calcium phosphate (PAsp-ACP) nanoparticles. HPMC which contains multiple hydroxyl groups is a film-forming material that can be desiccated to form a dry film. In a moist environment, this film gradually changes into a gel. HPMC was used as the carrier of PAsp-ACP nanoparticles to deliver biomimetic mineralization. Our results indicated that the hydroxyl and methoxyl groups of HPMC could assist the stability of PAsp-ACP nanoparticles and maintain their biomimetic mineralization activity. The results further demonstrated that the bioinspired mineralizing film induced the early mineralization of demineralized dentin after 24 h with increasing mineralization of the whole demineralized dentin (3-4 µm) after 72-96 h. Furthermore, these results were achieved without any cytotoxicity or mucosa irritation. Therefore, this mineralizing film shows promise for use in preventive dentistry due to its efficient mineralization capability.

Lipid nanocapsules loaded with prilocaine and lidocaine and incorporated in gel for topical application

Lipid nanocapsules (LNC) are special drug delivery system (DDS) carriers obtained by the phase-inversion temperature method (PIT). This study describes the encapsulation of the local anesthetics (LA) prilocaine (PLC) and lidocaine (LDC) in lipid nanocapsules (LNC_PLC+LDC) optimized by 2³ factorial design, characterized through DLS, NTA, CRYO-EM and release kinetics and incorporated in carbopol gel (Gel_{LNC PLC+LDC}) prior to in vivo anesthetic effect (in mice) evaluation. A very homogeneous population of small (50 nm; polydispersity index = 0.05) spherical nanocapsules with negative zeta potentials (-21 mV) and ca. 2.3 × 10¹⁵ particles/mL was obtained. The encapsulation efficiency was high (81% and 89% for prilocaine and lidocaine, respectively). The release rate profile was free PLC = free LDC > LNC_PLC+LDC > Gel_{LNC PLC+LDC}. The hybrid system increased (4x) the anesthesia time in comparison to an equipotent gel formulation prepared without LNC. No tissue damage was detected on the tail skin of mice that received the formulations. This study shows that lipid nanocapsules are suitable carriers for PLC and LDC, promoting longer and safer topical anesthesia. Gel_{LNC PLC+LDC} is mucoadhesive and suitable for application in the mouth, where it could be used as a pre-anesthetic, to reduce pain of needle stick (infiltrative anesthesia).

Enhanced drug loading of in situ forming gels for oral mucositis pain control

Localized delivery to oral mucositis ulcerations requires specialized dosage forms, (e.g. in situ forming gels) delivered to the site in relatively low volumes. However, this is challenging for drugs with low solubility such as Bupivacaine γ-Linoleate (Bup-γL). The objective of this study is to develop an in situ forming gel with enhanced loading of Bup-γL for oral mucositis pain control. Two co-solvents (PEG400 and ethanol) and eight solubilizers (Tween 80, sodium lauryl sulfate, Cremophor® RH40, Cremophor® EL, Kolliphor® HS 15, Soluplus®, PEG 3350 and PEG8000) were screened for their capability to solubilize Bup-γL. Among all tested solubilizers, sodium lauryl sulfate (SLS) showed the highest solubilizing capacity (8.83 ± 0.94 mg/mL). This was considered to be a consequence of the similarity between the structure of SLS and Bup-γL. On the addition of SLS to the in situ forming gels, the drug loading was enhanced from ~6.5 to ~10.5 mg/ml. The formulations were characterized for their gelation temperature, rheological properties, in vitro drug release and short-term storage stability. The gelation temperatures of the in situ forming gel formulations were significantly reduced with enhanced drug loading. The in vitro drug release profiles showed good fit to both the first order and the Higuchi models. Formulations with SLS demonstrated sustained drug release (time to plateau ~7 h) compared with formulations without SLS (time to plateau ~3.5 h). This study offers an effective strategy to enhance drug loading of in situ forming gels. The enhanced drug loading will reduce the dosing volume and as such is expected to reduce any unwanted numbing of the healthy mucosa.

Recent Advances in the Development of In Situ Gelling Drug Delivery Systems for Non-Parenteral Administration Routes

In situ gelling drug delivery systems have gained enormous attention over the last decade. They are in a sol-state before administration, and they are capable of forming gels in response to different endogenous stimuli, such as temperature increase, pH change and the presence of ions. Such systems can be administered through different routes, to achieve local or systemic drug delivery and can also be successfully used as vehicles for drug-loaded nano- and microparticles. Natural, synthetic and/or semi-synthetic polymers with in situ gelling behavior can be used alone, or in combination, for the preparation of such systems; the association with mucoadhesive polymers is highly desirable in order to further prolong the residence time at the site of action/absorption. In situ gelling systems include also solid polymeric formulations, generally obtained by freeze-drying, which, after contact with biological fluids, undergo a fast hydration with the formation of a gel able to release the drug loaded in a controlled manner. This review provides an overview of the in situ gelling drug delivery systems developed in the last 10 years for non-parenteral administration routes, such as ocular, nasal, buccal, gastrointestinal, vaginal and intravesical ones, with a special focus on formulation composition, polymer gelation mechanism and in vitro release studies.