Core-shell alginate-ghatti gum modified montmorillonite composite matrices for stomach-specific flurbiprofen delivery

Preparation and characterization of pectin-alginate-based microbeads reinforced by nano montmorillonite filler for probiotics encapsulation: Improving viability and colonic colonization

Hydrogel microbeads can be used to enhance the stability of probiotics during gastrointestinal delivery and storage. In this study, the pectin-alginate hydrogel was enhanced by adding montmorillonite filler to produce microbeads for encapsulating Lactobacillus kefiranofaciens (LK). Results showed that the viscosity of biopolymer solutions with 1 % (PAMT1) and 3 % (PAMT3) montmorillonite addition was suitable for producing regular-shaped microbeads. A layered cross-linked network was formed on the surface of PAMT3 microbeads through electrostatic interaction between pectin-alginate and montmorillonite filler, and the surrounding LK with adsorbed montmorillonite was encapsulated inside the microbeads. PAMT3 microbeads reduced the loss of viability of LK when passing through the gastric acid environment, and facilitated the slow release of LK in the intestine and colonic colonization. The maximum decrease in viability among all filler groups was 1.21 log CFU/g after two weeks of storage, while PAMT3 freeze-drying microbeads only decreased by 0.46 log CFU/g, indicating that the gel layer synergized with the adsorbed layer to provide dual protection for probiotics. Therefore, filler-reinforced microbeads are a promising bulk encapsulation carrier with great potential for the protection and delivery of probiotics and can be developed as food additives for dairy products.

Nanohybrid Based on (Mn, Zn) Ferrite Nanoparticles Functionalized With Chitosan and Sodium Alginate for Loading of Curcumin Against Human Breast Cancer Cells

This study reports on the synthesis of Mn1 - xZnxFe2O4 (Mn, Zn ferrite) magnetic nanoparticles (MNPs) as drug delivery carriers for effective therapeutic outcomes. The MNPs were prepared using the coprecipitation method, and their magnetic properties were investigated based on their composition. Among the compositions tested, Mn0.8Zn0.2Fe2O4 MNPs exhibited superparamagnetic properties with a saturation magnetization moment of 34.6 emu/g at room temperature (25°C). To enhance the water solubility of curcumin (Cur), known for its hydrophobic nature, it was successfully loaded onto alginate (Alg)/chitosan (Chit)@Mn0.8Zn0.2Fe2O4 nanoparticles (NPs). The nanocomposite was characterized by field emission scanning electron microscopy (FE-SEM) which revealed a particle size of approximately 20 nm. The crystalline structure of the NPs was analyzed using X-ray diffraction, while Fourier-transform infrared (FTIR), energy-dispersive X-ray, and map analysis techniques were employed for further characterization. In terms of drug release, there was an initial burst release of Cur (around 18%) within the first hour, followed by a slower release (approximately 61%) over the next 36 h. The anti-tumor properties of the Cur-loaded NPs were evaluated using the Methyl Thiazol Tetrazolium (MTT) assay and quantitative real-time polymerase chain reaction. The MTT assay confirmed a higher cytotoxic effect of Cur-loaded Alg/Chit@Mn0.8Zn0.2Fe2O4 NPs on the MCF-7 breast cancer cell line compared to free Cur, highlighting the significance of incorporating Cur into nano-sized carrier systems.

Mucoadhesive carriers for oral drug delivery

Among the various dosage forms, oral medicine has extensive benefits including ease of administration and patients' compliance, over injectable, suppositories, ocular and nasal. Despite of extensive demand and emerging advantages, over 50% of therapeutic molecules are not available in oral form due to their physicochemical properties. More importantly, most of the biologics, proteins, peptide, and large molecular drugs are mostly available in injectable form. Conventional oral drug delivery system has limitation such as degradation and lack of stability within stomach due to presence of highly acidic gastric fluid, hinders their therapeutic efficacy and demand more frequent and higher dosing. Hence, formulation for controlled, sustained, and targeted drug delivery, need to be designed with feasibility to target the specific region of gastrointestinal (GI) tract such as stomach, small intestine, intestine lymphatic, and colon is challenging. Among various oral delivery approaches, mucoadhesive vehicles are promising and has potential for improving oral drug retention and controlled absorption to treat local diseases within the GI tract, as well systemic diseases. This review provides the overview about the challenges and opportunities to design mucoadhesive formulation for oral delivery of therapeutics in a way to target the specific region of the GI tract. Finally, we have concluded with future perspective and potential of mucoadhesive formulations for oral local and systemic delivery.

Alginate as a Promising Biopolymer in Drug Delivery and Wound Healing: A Review of the State-of-the-Art

Biopolymeric nanoparticulate systems hold favorable carrier properties for active delivery. The enhancement in the research interest in alginate formulations in biomedical and pharmaceutical research, owing to its biodegradable, biocompatible, and bioadhesive characteristics, reiterates its future use as an efficient drug delivery matrix. Alginates, obtained from natural sources, are the colloidal polysaccharide group, which are water-soluble, non-toxic, and non-irritant. These are linear copolymeric blocks of α-(1→4)-linked l-guluronic acid (G) and β-(1→4)-linked d-mannuronic acid (M) residues. Owing to the monosaccharide sequencing and the enzymatically governed reactions, alginates are well-known as an essential bio-polymer group for multifarious biomedical implementations. Additionally, alginate’s bio-adhesive property makes it significant in the pharmaceutical industry. Alginate has shown immense potential in wound healing and drug delivery applications to date because its gel-forming ability maintains the structural resemblance to the extracellular matrices in tissues and can be altered to perform numerous crucial functions. The initial section of this review will deliver a perception of the extraction source and alginate’s remarkable properties. Furthermore, we have aspired to discuss the current literature on alginate utilization as a biopolymeric carrier for drug delivery through numerous administration routes. Finally, the latest investigations on alginate composite utilization in wound healing are addressed.

Improving the 6-Aminopenicillanic acid release process using vermiculite-alginate biocomposite bead on drug delivery system

The present study deals with developing vermiculite (VMT)-alginate (Alg) composites with different cross-linker concentrations (CaCl₂) to deliver the controlled 6-aminopenicillin acid (6-APA). The Characterization of synthesized composites was conducted by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. Optimization attempts were explored via the response surface method (RSM) to best predict the actual amount of compound. The adsorption capacity of 6-APA onto this adsorbent was found to be 208.33 mg/g, which was higher than that for other clays. The equilibrium and Kinetic studies (chemical reaction and diffusion-based models) indicated that drug absorption on VMT-Alg is homogeneous with chemical interaction. An increase in cross-linker (CaCl₂) concentration leads to improvement in the drug encapsulation efficiency while having no significant effect on loading efficiency. The in-vitro release of the pure drug shows a rapid burst release followed by 100% cumulative release within 6 h. Whereas, the synthesized drug with Alg substantially showed less release of 43% after 8 h. Release experiments revealed that the presence of the CaCl₂ delayed the release of the 6-APA less than 35% after 12 h. The kinetic release of 6-APA is followed by the Korsmeyer-Peppas model based on Fick's law mechanism due to the kinetic exponent (n < 0.5). All studied composites antibacterial activity after 24 h exposure against E. Coli and S. aureus. The antibacterial activities of composites were evaluated by the halo of no growth. The results showed that the VMT-Alg-6APA composite had strong activity against Gram-positive and Gram-negative bacteria.

Hybrid Hosts Based on Sodium Alginate and Porous Clay Heterostructures for Drug Encapsulation

In this study, some hybrid materials based on sodium alginate (NaAlg) and porous clay heterostructures (PCHs) were investigated as new hosts for 5-Fluorouracil (5-FU) encapsulation. The hybrid hosts were prepared by ionotropic gelation technique using different concentrations of PCHs (1, 3, and 10 wt%) in order to identify the optimal parameters for encapsulation and drug release. The obtained hybrid materials were characterized using FTIR Spectrometry, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and UV-Vis spectrometry to investigate the interactions of the raw materials involved in the preparation of hybrid hosts, the influence of PCHs concentrations on drug encapsulation efficiency and drug release profile. All the results show that the synthesized hybrid materials were able to load a high amount of 5-FU, the encapsulation efficiency and the release profile being influenced by the concentrations of PCHs.

Electro-hydrodynamic assisted synthesis of lecithin-stabilized peppermint oil-loaded alginate microbeads for intestinal drug delivery

Peppermint oil (PO) is the most prominent oil using in pharmaceutical formulations with its significant therapeutic value. In this sense, this oil is attracting considerable attention from the scientific community due to its traditional therapeutic claim, biological and pharmacological potential in recent research. An organic solvent-free and environment-friendly electrohydrodynamic assisted (EHDA) technique was employed to prepared PO-loaded alginate microbeads. The current study deals with the development, optimization, in vitro characterization, in vivo gastrointestinal tract drug distribution and ex-vivo mucoadhesive properties, antioxidant, and anti-inflammatory effects of PO-loaded alginate microbeads. The optimization results indicated the voltage and flow rate have a significant influence on microbeads size and sphericity factor and encapsulation efficiency. All these optimized microbeads showed a better drug release profile in simulated intestinal fluid (pH 6.8) at 2 h. However, a minor release was found in acidic media (pH 1.2) at 2 h. The optimized formulation showed excellent mucoadhesive properties in ex-vivo and good swelling characterization in intestine media. The microbeads were found to be well distributed in various parts of the intestine in in vivo study. PO-loaded alginate microbeads similarly showed potential antioxidant effects with drug release. The formulation exhibited possible improvement of irritable bowel syndrome (IBS) in MO-induced rats. It significantly suppressed proinflammatory cytokines, i.e., interleukin- IL-1β, and upregulated anti-inflammatory cytokine expression, i.e., IL-10. It would be a promising approach for targeted drug release after oral administration and could be considered an anti-inflammatory therapeutic strategy for treating IBS.

Chemosensitivity assessments of curdlan-doped smart nanocomposites containing erlotinib HCl

Curdlan (CN)-doped montmorillonite/poly(N-isopropylacrylamide-co-N,N'-methylene-bis-acrylamide) [CN/MT/P(NIPA-co-MBA)] smart nanocomposites (NCs) were developed for efficient erlotinib HCl (ERL) delivery to lung cancer cells. The placebo NCs demonstrated excellent biodegradability, pH/thermo-responsive swelling profiles and declined molar mass (M¯c) between the crosslinks with increasing temperature. The XRD, FTIR, DSC, TGA, and SEM analyses revealed the architectural chemistry of these NC scaffolds. The NCs loaded with ERL (F-1-F-3) displayed acceptable diameter (734-1120 nm) and zeta potential (+1.16 to -11.17 mV), outstanding drug entrapping capability (DEE, 78-99%) and sustained biphasic ERL elution patterns (Q_8h, 53-91%). The ERL release kinetics of the optimal matrices (F-3) obeyed Higuchi model and their transport occurred through anomalous diffusion. The mucin adsorption behaviour of these matrices followed Freudlich isotherms. As compared to pure ERL, the formulation (F-3) displayed an improved anti-proliferative potential and induced apoptosis more effectively on A549 cells. Thus, the CN-doped smart NCs could be utilized as promising drug-cargoes for lung cancer therapy.

Opportunities and Challenges in Tunneling Nanotubes Research: How Far from Clinical Application?

Tunneling nanotubes (TNTs) are recognized long membrane nanotubes connecting distance cells. In the last decade, growing evidence has shown that these subcellular structures mediate the specific transfer of cellular materials, pathogens, and electrical signals between cells. As intercellular bridges, they play a unique role in embryonic development, collective cell migration, injured cell recovery, cancer treatment resistance, and pathogen propagation. Although TNTs have been considered as potential drug targets for treatment, there is still a long way to go to translate the research findings into clinical practice. Herein, we emphasize the heterogeneous nature of TNTs by systemically summarizing the current knowledge on their morphology, structure, and biogenesis in different types of cells. Furthermore, we address the communication efficiency and biological outcomes of TNT-dependent transport related to diseases. Finally, we discuss the opportunities and challenges of TNTs as an exciting therapeutic approach by focusing on the development of efficient and safe drugs targeting TNTs.

Interaction among clays and bovine serum albumin

Interactions between bovine serum albumin and various clays including pure clay minerals and bentonite were studied with the aim to describe the interaction process. The adsorption of albumin on the clays is strongly affected by the behavior of clays in the aquatic environment (hydrolysis and release of cations). A sufficient amount of albumin was adsorbed on the acid-activated montmorillonite K10 (0.067 mg mg⁻¹) and on the illite–smectite (0.086 mg mg⁻¹). These clay minerals do not strongly affect the sorption solution parameters such as pH value and content of cations. Practically no adsorption was observed on the bentonite and vermiculite. Bentonite and vermiculite are subject to stronger interactions with water which cause the increase of pH value of the sorption solution and release of cations to the solution and thus they cause conformational changes of albumin, which was confirmed by circular dichroism measurements. Obtained results were confirmed by infrared spectroscopy and thermal analysis as well. Interaction of studied materials with bovine serum albumin causes the reduction of particle size in the case of all studied clays except vermiculite. Albumin probably attacks the clay structure during the adsorption, which causes the decrease of particle size. The presented work contributes to the knowledge about interaction of bovine serum albumin with clays in the field of influence of physico-chemical behaviour of clays in the solution on the interaction with albumin.

Interaction of bovine serum albumin with clays strongly affects the structure of both clay and protein.

Curcumin encapsulated dual cross linked sodium alginate/montmorillonite polymeric composite beads for controlled drug delivery

The aim of the present work is fabrication of dual cross linked sodium alginate (SA)/montmorillonite (MMT) microbeads as a potential drug vehicle for extended release of curcumin (CUR). The microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique. The developed beads were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (X-RD) and scanning electron microscopy (SEM). The effect of MMT on encapsulation efficiency of CUR and intercalation kinetics was investigated. Dynamic swelling study and in vitro release study were investigated in simulated intestinal fluid (pH 7.4) and simulated gastric fluid (pH 1.2) at 37 °C. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. The release mechanism was analyzed by fitting the release data into Korsmeyer-Peppas equation.

•

The microbeads prepared using sodium alginate (SA)/montmorillonite (MMT) were found to be potentially good carriers of curcumin (CUR) for extended release of CUR.

•

The bioavailability of CUR is increased by the usage of MMT in the microbeads, hence making it possible to enhance the anti-tumour activity.

•

The incorporation of multivalent ions like Mg²⁺, Ba²⁺ and Al³⁺ into calcium alginate matrix modified the swelling property and release rate of bio-active molecules.

•

The porous nature of the microbeads was based on the size and interaction of the ions namely Mg²⁺, Ba²⁺ and Al³⁺ with alginate.

Development and Characterization of PCL Electrospun Membrane-Coated Bletilla striata Polysaccharide-Based Gastroretentive Drug Delivery System

The purpose of this study was to investigate the potential of Bletilla striata polysaccharide (BSP, a natural glucomannan material) for the development of a gastroretentive drug delivery system for the first time. Novel BSP-based porous wafer was prepared for levofloxacin hydrochloride (LFH) delivery by combining floating, swelling, and mucoadhesion mechanisms. The influences of BSP and ethyl cellulose (EC) on drug release and mucoadhesive strength were studied by 3² factorial design. The optimized matrix was coated with polycaprolactone (PCL) electrospun membrane by electrospinning and heat treatment technology. The optimized formula (F6, coated) exhibited Q_4 h of 41.20 ± 1.90%, Q_8 h of 76.49 ± 1.69%, and mucoadhesive strength of 86.11 ± 1.33 gf, and its drug release profile most closely resembled the Korsmeyer-Peppas model with anomalous diffusion driving mechanism. F6 (coated) also presented excellent buoyancy, preferred swelling characteristic due to the porous structure formed by freeze-drying. Meanwhile, the internal morphology, physical state, drug-excipient compatibility, and thermal behavior were recorded. The negligible cytotoxicity of F6 (coated) was observed in human gastric epithelial cell cultures. In the in vitro antimicrobial experiment, the prepared wafer exhibited obvious bacterial inhibition zone, and due to its longer gastric retention, the wafer also performed a more effective Helicobacter pylori clearance than free LFH in vivo. Graphical abstract.

Incorporation of Fmoc-Y nanofibers into Ca-alginate hydrogels for improving their mechanical properties and the controlled release of small molecules

A robust interpenetrating network (IPN) hydrogel was assembled from calcium alginate and Fmoc-tyrosine for the controlled release of small molecules.

Polymer brush hexadecyltrimethylammonium bromide (CTAB) modified poly (propylene-g-styrene sulphonic acid) fiber (ZB-1): CTAB/ZB-1 as a promising strategy for improving the dissolution and physical stability of poorly water-soluble drugs

The feasibility of polymer brush as drug delivery vehicle was demonstrated with the goal of improving the dissolution and physical stability of poorly water-soluble drugs. Polymer brush CTAB/ZB-1 was synthesized by electrostatic interaction using a physical modification method with anionic poly (propylene-g-styrene sulphonic acid) fiber (ZB-1) as the substrate and cationic hexadecyltrimethylammonium bromide (CTAB) as the modifier. The polymer brush structure of CTAB/ZB-1 was validated by atomic force microscopy (AFM) and the channels of brush provided the drug loading sites. Flurbiprofen (FP), a BCS class II representative drug, was selected as the model poorly water-soluble drug to be loaded into this polymer brush. Then the drug loading and release were systematically investigated. Besides, the transformation from crystalline FP to amorphous state was observed by differential scanning calorimeter (DSC). In vitro dissolution in pure water and pH1.2 HCl media with/without 0.1% sodium dodecyl sulfate (SDS) was tested. Moreover, the optimal formulations (namely carrier/drug ratios) were determined. The results demonstrated prominent improvement of dissolution when FP was released from CTAB/ZB-1. After a long time storage, FP remained amorphous in CTAB/ZB-1 according to DSC determinations and performed an approximately equivalent dissolution compared with fresh samples, suggesting the advantage of CTAB/ZB-1 as carrier in enhancing the physical stability of drugs. The study introduced the versatile easily formulated polymer brush CTAB/ZB-1 and demonstrated the potential of polymer brush as an alternative approach for improving the dissolution and physical stability of poorly water-soluble drugs.