In vitro drug release profiles of pH-sensitive hydroxyethylacryl chitosan/sodium alginate hydrogels using paracetamol as a soluble model drug

Alginate/hyaluronic acid/gelatin ternary blended films as pH-sensitive drug carriers: In vitro ampicillin release and kinetic studies

Researchers continuously focused on the fabrication of innovative drug delivery systems to prevent microbial infections while minimizing systemic side effects. Among these, pH-sensitive antibiotic release systems based on bio-based materials have gained great attention due to their ability to precisely modulate drug kinetics and enhance therapeutic efficacy. Herein, pH-sensitive alginate/hyaluronic acid/gelatin ternary blended films were fabricated for the controlled release of ampicillin. Swelling capacity, hydrolytic degradation profile, pH reversibility and in vitro ampicillin release behavior of produced films were investigated in both simulated gastric (pH 1.2) and intestinal (pH 7.4) environments. The cumulative release amount of ampicillin at pH 1.2 (61.0 ± 1.07 mg drug/g polymer) was greater than that of at pH 7.4 (43.0 ± 1.05 mg drug/g polymer) proved that release behavior of ampicillin for produced films is pH-dependent. Based on the fitted release data, best fit was found as the first-order kinetic model with the highest R2 values of 0.966 and 0.962 for both pH conditions. According to Korsmeyer-Peppas model, drug release mechanism is also controlled by case II-transport. Furthermore, produced films demonstrated excellent cytocompatibility. All results revealed that obtained films could be a promising drug carrier to traditional targeting systems for site-specific, pH-sensitive ampicillin delivery in both gastric and intestine.

Ca2+-mediated chitosan/sodium alginate encapsulated Red Monascus Pigment hydrogel beads: Preparation, characterization and release kinetics

Red Monascus Pigment (RMP), a natural pigment, has attracted significant attention due to its suitability for food use and potential health benefits. However, preserving its stability and exploring value-added development opportunities remain crucial challenges. This study outlined the utilization of RMP, by successfully preparing hydrogel beads encapsulating RMP crude extract (RMPCE) through Ca2+-mediated chitosan (CS)/sodium alginate (SA) encapsulation (CO-RMPHB). A systematic investigation into the fabrication and stability parameters, including preparation conditions, temperature, monochromatic light and storage time, was undertaken. Through optimization (SA: 2.50 wt%; CaCl2: 6.00 wt%; CS: 0.50 wt%), maximum encapsulation efficiency of 73.54 ± 2.16 % was achieved. The maximum swelling degree of blank hydrogel beads (BHB) in simulated gastric solution (pH = 1.2, 1.50 ± 0.97 %) was significantly lower than in simulated intestinal solution (pH = 7.0, 28.05 ± 1.43 %), confirming their sensitivity to pH changes. Additionally, the CO-RMPHB (66.08 %, 1000 μL) exhibited superior DPPH radical scavenging capability compared to individual RMPCE or BHB. Furthermore, analysis of the release kinetics based on zero-order, first-order, Higuchi, and Ritger-Peppas models revealed that RMPCE release from CO-RMPHB under in vitro digestion models followed non-Fickian diffusion. This discovery effectively addresses the challenges of the stability and controlled release of RMP, expanding its applications in the food and pharmaceutical industries.

Membrane fouling characteristics and mechanisms in coagulation-ultrafiltration process for treating microplastic-containing water

Microplastics (MPs) are recognized as a significant challenge to water treatment processes due to their ability to adsorb or accumulate alginate foulants, impacting the coagulation-ultrafiltration (CUF) process. In this study, the mechanisms of membrane fouling caused by MPs under varying dosages of polymeric aluminum chloride (PAC) coagulant in the CUF process were investigated. It was revealed that MPs contribute to membrane fouling, which initially intensifies and then alleviates as coagulant concentration increases, with a turning point at 0.05 mM PAC dosage. The most significant alleviation of membrane fouling was observed at 0.2 mM PAC dosage. An in-depth analysis of interfacial interaction energy changes during filtration was conducted using the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, demonstrating how MPs alter the interaction forces between foulants and the membrane surface, leading to either the exacerbation or mitigation of fouling. Additionally, it was shown that at optimal coagulant concentrations, the presence of MPs promotes the formation of a loose and porous cake layer, disrupting the original structure and creating a more open block structure, thereby alleviating membrane fouling. These findings provide valuable insights for optimizing the CUF process in microplastic-containing water treatment, presenting a novel approach to enhancing efficiency and reducing membrane fouling.

Encapsulation, characterization and in vitro releasing of xylanase and glucose oxidase (GOD) into cellulose nanocrystals stabilized three-layer microcapsules

The xylanase and glucose oxidase (GOD) are easily inactivated, restricting their applicaiton in food and agriculture fields. In this work, xylanase and glucose oxidase (GOD) were encapsulated into cellulose nanocrystals (CNC) stabilized three-layer microcapsules via ionic gelation technique to improve their bioavailability and targeted delivery. Encapsulation efficiency (EE), physicochemical properties, and in vitro releasing of xylanase and GOD encapsulated in microcapsules were investigated. EE of xylanase and GOD reached the highest values (73.34 % and 67.16 %, respectively) at an enzyme concentration of 35 mg/mL. In vitro experiments revealed that cumulative release of both enzymes encapsulated in microcapsules was greater than that of controls in simulated gastric tract (SGT) and simulated intestinal tract (SIT). The release of xylanase increased from 41.62 % (gastric tract) to 77.13 % (intestine tract), and release of GOD increased from 42.63 % to 72.11 %, respectively. Novel hydrogel carriers as enzymes encapsulation system could effectively improve the survival rate of enzymes in harsh environments and could be widely employed in food, feed and other industries.

Oral Patch/Film for Drug Delivery-Current Status and Future Prospects

In recent years, there has been extensive research into drug delivery systems aimed at enhancing drug utilization while minimizing drug toxicities. Among these systems, oral patches/films have garnered significant attention due to their convenience, noninvasive administration, ability to bypass hepatic first-pass metabolism, thereby enhancing drug bioavailability, and their potential to ensure good compliance, particularly among special patient populations. In this review, from the perspective of the anatomical characteristics of the oral cavity and the advantages and difficulties of oral drug delivery, we illustrate the design ideas, manufacturing techniques, research methodologies, and the essential attributes of an ideal oral patch/film. Furthermore, the applications of oral patches/films in both localized and systemic drug delivery were discussed. Finally, we offer insights into the future prospects of the oral patch/film, aiming to provide valuable reference for the advancement of oral localized drug delivery systems.

Effect of Mn2+ on RO membrane organic fouling: Insights into the complexation and interfacial interaction

RO process is commonly used to treat and reuse manganese-containing industrial wastewater. Nevertheless, even after undergoing multi-stage treatment, the secondary biochemical effluent still exhibits a high concentration of Mn2+ coupled with organics entering the RO system, leading to membrane fouling. In this work, we systematically analyze the RO membrane organic fouling processes and mechanisms, considering the coexistence of Mn2+ with humic acid (HA), sodium alginate (SA), bovine serum albumin (BSA) and their mixtures (HBS). The impact of Mn2+ on membrane fouling was HBS > SA > HA > BSA, controlling polysaccharide pollutant concentrations should be a priority for mitigating membrane fouling. In the presence of Mn2+ with HA, SA, or HBS, membrane fouling is primarily attributed to the complexation of organics and Mn2+ and the facilitation of interfacial interaction energy. RO membrane BSA fouling was not directly affected by Mn2+, the addition of Mn2+ induced a salting-out effect, leading to the deposition of BSA in a single molecular on the membrane. Simultaneously, adhesion energy hinders the deposition of BSA on the membrane, resulting in milder membrane fouling. This study provided the theoretical basis and suggestions for RO membrane organic fouling control in the presence of Mn2+.

Evaluation of drug release efficiency and antibacterial property of a pH-responsive dextran-based silver nanocomposite hydrogel

The bioavailability of curcumin (CUR), a highly lipophilic and commonly used anticancer drug, is mainly affected by its poor solubility in aqueous environment and quick metabolism. These challenges can be met by employing delivery systems. Nanocomposite materials have been used as delivery systems to enhance the solubility and dissolution rate of the drug. This study aims to develop dextran-graft-poly(4-acryloylmorpholine) silver nanocomposite using a microwave-assisted method to evaluate its drug-release efficiency and antimicrobial activity. The materials were characterized by FT-IR, FE-SEM, EDS, XRD, HR-TEM, TGA, and BET techniques. Drug loading and release efficiency were evaluated using CUR as the model drug. The swelling and drug release studies were conducted in buffer solutions of pH 1.2 and 7.4. Staphylococcus aureus and Escherichia coli were employed to evaluate the antibacterial activity. The cytotoxicity was assessed by MTT assay against the breast MCF-10. Higher swelling and drug release were observed at pH 1.2 than 7.4. Nanocomposite hydrogel exhibited antibacterial activity against the tested bacterial strains. Cytotoxicity study proved the safety of the developed matrix. The results suggest the developed nanocomposite hydrogel to be a promising polymer matrix for the sustained release of CUR for cancer treatment that requires infectious control.

Unveiling a pH-Responsive Dual-Androgen-Blocking Magnetic Molecularly Imprinted Polymer for Enhanced Synergistic Therapy of Prostate Cancer

Prostate cancer is the most common malignancy diagnosed in men. Androgens are directly related to its pathogenesis. Inhibition of the androgen receptor (AR) is considered to be the most promising therapeutic approach for the treatment of prostate cancer. In this study, a new type of pH-responsive dual androgen-blocking nanodrug (FASC MIPs) based on a molecularly imprinted polymer has been designed and synthesized. The nanodrug could selectively sequester testosterone from the prostate tumor through specific molecular imprinting sites and simultaneously deliver the AR inhibitory drug bicalutamide, which ultimately leads to enhanced synergistic therapy of prostate cancer. FASC MIPs demonstrate excellent pH responsiveness in a simulated tumor microenvironment due to the presence of chitosan and significantly inhibit the growth of prostate cancer cells (LNCaP cells) by blocking the G1 phase of cytokinesis. Additionally, the nanodrug also displayed excellent antitumor properties in a xenograft mouse model of prostate cancer without any sign of detrimental effects on healthy tissues and organs. Both in vitro and in vivo studies verified the augmented and synergistic therapeutic effects of FASC MIPs, and the proposed dual-androgen-blocking strategy could explore novel avenues in prostate cancer treatment.

Development of Efficient Sodium Alginate/Polysuccinimide-Based Hydrogels as Biodegradable Acetaminophen Delivery Systems

Efficient drug delivery systems are essential for improving patient outcomes. Acetaminophen (AP), which is a kind of oral administration, is a commonly used pain reliever and fever reducer. However, oral administration carries various health risks, especially overdose and frequent use; for instance, AP is administered approximately 4 times per day. Therefore, the aim of this study is to develop an efficient delivery system for once-daily administration by combining sodium alginate and polysuccinimide (PSI) hydrogels to delay the release of analgesic AP. PSI is a biodegradable polymer that can be used safely and effectively in drug delivery systems because it is eliminated by hydrolysis in the intestine. The use of PSI also improves the mechanical properties of hydrogels and prolongs drug release. In this study, hydrogel characterizations such as mechanical properties, drug dissolution ability, and biodegradability were measured to evaluate the hydrolysis of PSI in the intestine. Based on the results, hydrogels could be designed to improve the structural mechanical properties and to allow the drug to be completely dissolved, and eliminated from the body through PSI hydrolysis in the intestines. In addition, the release profiles of AP in the hydrogels were evaluated, and the hydrogels provided continuous release of AP for 24 h. Our research suggests that sodium alginate/PSI hydrogels can potentially serve as biodegradable delivery systems for AP. These findings may have significant implications for developing efficient drug delivery systems for other classes of drugs.

Microsponge-Based Gel Loaded with Immunosuppressant as a Simple and Valuable Strategy for Psoriasis Therapy: Determination of Pro-Inflammatory Response through Cytokine IL-2 mRNA Expression

Tacrolimus (TL) is a topical calcineurin inhibitor immunosuppressive drug widely used to manage various skin disorders. Herein, we report a TL-loaded microsphere gel formulation with severe atopic dermatitis effects that are required to manage skin disorders. The current study adopted a modified emulsion solvent evaporation technique to synthesize TL-loaded microspheres, which were further converted into gels for skin use. Characterization of the synthesized formulation was performed by differential dynamic light scattering, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray crystallography, Brunauer-Emmett-Teller (BET) analysis, differential scanning calorimetry, and drug release. A Franz diffusion cell was used to study the diffusion of TL for up to 8 h at pH 6.8 and 5.5. Evaluation of cell viability was determined by MTT assay and showed higher IC50 values compared to the plain drug. RNA extraction, real-time polymerase chain reaction (RT-PCR), and reverse transcription were also performed to determine the expression levels of the anti-inflammatory cytokine IL-2. Particle size determination was performed by a zeta sizer, and the TL microsphere size was 1745 ± 70 nm with a good polydispersity (0.337 ± 0.12). The drug entrapment efficiency was also very good at 60% ± 10, and the drug release was 93.9% ± 3.5 within 8 h. An in vitro diffusion study of the formulation also showed improved permeability at both pH values (4.5 and 5.5). The findings of the hemolytic tests demonstrated that TL-MG at concentrations of 50, 100, and 200 mg/mL did not produce any hemolysis. A dose-dependent pattern of cytotoxicity was found during the cell viability assay, with an IC50 value of 787.55 ± 12.78 µg/mL. There was a significant decrease in the IL-2 level in the TL-MG group compared to the other groups. TL-MG microspheres were nontoxic carriers for tacrolimus delivery, with greater loading capacity, a significant release profile, and enhanced cellular uptake with improved permeability.

Double network structure via ionic bond and covalent bond of carboxymethyl chitosan and poly(ethylene glycol): Factors affecting hydrogel formation

The factors were studied that affect the formation of DN hydrogel, which was prepared using a water-based, environmental-friendly system. The DN hydrogel was designed and prepared based on a cross-linked, polysaccharide-based, polymer carboxymethyl chitosan (CMCS) via an ionic crosslinking reaction for the first network structure. UV irradiation created a radical crosslinking reaction of poly(ethylene glycol) from a double bond at the chain end for the second network structure. It was found that the optimum hydrogel was produced using 9.5 %v/v of 1000PEGGMA, CMCS 5%w/v, and CaCl₂ 3%w/v. The results showed the highest percentage of the gel fraction was 87.84 % and the hydrogel was stable based on its rheological properties. Factors affecting the hydrogel formation were the concentration and molecular weight of PEGGMA and the concentrations of CMCS and calcium chloride (CaCl₂). The DN hydrogel had bioactivity due to its octacalcium phosphate (OCP) hydroxyapatite crystal form. In addition, the composite DN scaffold with a conductive polymer of chitosan-grafted-polyaniline (CS-g-PANI) had conduction of 2.33 × 10^-5 S/cm when the concentration of CS-g-PANI was 3 mg/ml, confirming the semi-conductive nature of the material. All the results indicated that DN hydrogel could be a candidate to apply in tissue-engineering applications.

Self-assembled carboxymethyl chitosan/zinc alginate composite film with excellent water resistant and antimicrobial properties for chilled meat preservation

A major way to reduce meat waste is to extend the shelf life of chilled meat with appropriate packaging. However, most of the packaging film cannot keep meat fresh because of its poor antibacterial and water resistance performance. In this paper, a composite film for chilled meat packaging was synthesized by simple self-assembly of zinc ions with chelating carboxyl groups. Introducing zinc ions into the composite system endows excellent water resistance and antibacterial properties to the film, which are demonstrated by the water vapor permeability and Escherichia coli and Staphylococcus aureus antibacterial tests. The as-prepared composite film also showed enhanced mechanical properties due to the formation of chelation bonds between zinc ions and carboxyl groups. Moreover, the chilled meat preservation test demonstrated the as-prepared composite film can significantly extend the shelf life of pork by five days, indicating its outstanding freshness preservation property. This work demonstrated a facile method to synthesize water-resistant and antimicrobial composite film, which can appear as an effective packaging material for chilled meat and offer a new idea to solve its short shelf-life problem.

Sodium Alginate/Chitosan-Coated Liposomes for Oral Delivery of Hydroxy-α-Sanshool: In Vitro and In Vivo Evaluation

BACKGROUND

Hydroxy-α-Sanshool (HAS) possesses various pharmacological properties, such as analgesia and regulating gastrointestinal function. However, the low oral bioavailability of HAS has limited its oral delivery in clinical application.

METHODS AND RESULTS

To enhance its oral bioavailability, a nanocomposite delivery system based on chitosan (CH, as the polycation) and sodium alginate (SA, as the polyanion) was prepared using a layer-by-layer coating technique. The morphology, thermal behavior and Fourier transform infrared spectrum (FTIR) showed that the obtained sodium alginate/chitosan-coated HAS-loaded liposomes (SA/CH-HAS-LIP) with core-shell structures have been successfully covered with polymers. When compared with HAS-loaded liposomes (HAS-LIP), SA/CH-HAS-LIP displayed obvious pH sensitivity and a sustained-release behavior in in vitro studies, which fitted well to Weibull model. In vivo, the half-life of HAS from SA/CH-HAS-LIP remarkably extended after oral administration compared to the free drug. Additionally, it allowed a 4.6-fold and 4.2-fold increase in oral bioavailability, respectively, compared with free HAS and HAS-LIP.

CONCLUSIONS

SA/CH-HAS-LIP could be a promising release vehicle for the oral delivery of HAS to increase its oral bioavailability.

Electro-Responsive Conductive Blended Hydrogel Patch

The proposed electro-responsive hydrogel has great benefit for transdermal drug delivery system (TDDS) applications. To improve the physical or chemical properties of hydrogels, a number of researchers have previously studied the mixing efficiencies of the blended hydrogels. However, few studies have focused on improving the electrical conductivity and drug delivery of the hydrogels. We developed a conductive blended hydrogel by mixing alginate with gelatin methacrylate (GelMA) and silver nanowire (AgNW). We demonstrated that and the tensile strength of blended hydrogels were increased by a factor of 1.8 by blending GelMA and the electrical conductivity was enhanced by a factor of 18 by the addition of AgNW. Furthermore, the GelMA-alginate-AgNW (Gel-Alg-AgNW) blended hydrogel patch enabled on-off controllable drug release, indicating 57% doxorubicin release in response to electrical stimulation (ES) application. Therefore, this electro-responsive blended hydrogel patch could be useful for smart drug delivery applications.

Tailoring Magnetite-Nanoparticle-Based Nanocarriers for Gene Delivery: Exploiting CRISPRa Potential in Reducing Conditions

Gene delivery has emerged as a promising alternative to conventional treatment approaches, allowing for the manipulation of gene expression through gene insertion, deletion, or alteration. However, the susceptibility of gene delivery components to degradation and challenges associated with cell penetration necessitate the use of delivery vehicles for effective functional gene delivery. Nanostructured vehicles, such as iron oxide nanoparticles (IONs) including magnetite nanoparticles (MNPs), have demonstrated significant potential for gene delivery applications due to their chemical versatility, biocompatibility, and strong magnetization. In this study, we developed an ION-based delivery vehicle capable of releasing linearized nucleic acids (tDNA) under reducing conditions in various cell cultures. As a proof of concept, we immobilized a CRISPR activation (CRISPRa) sequence to overexpress the pink1 gene on MNPs functionalized with polyethylene glycol (PEG), 3-[(2-aminoethyl)dithio]propionic acid (AEDP), and a translocating protein (OmpA). The nucleic sequence (tDNA) was modified to include a terminal thiol group and was conjugated to AEDP's terminal thiol via a disulfide exchange reaction. Leveraging the natural sensitivity of the disulfide bridge, the cargo was released under reducing conditions. Physicochemical characterizations, including thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the correct synthesis and functionalization of the MNP-based delivery carriers. The developed nanocarriers exhibited remarkable biocompatibility, as demonstrated by the hemocompatibility, platelet aggregation, and cytocompatibility assays using primary human astrocytes, rodent astrocytes, and human fibroblast cells. Furthermore, the nanocarriers enabled efficient cargo penetration, uptake, and endosomal escape, with minimal nucleofection. A preliminary functionality test using RT-qPCR revealed that the vehicle facilitated the timely release of CRISPRa vectors, resulting in a remarkable 130-fold overexpression of pink1. We demonstrate the potential of the developed ION-based nanocarrier as a versatile and promising gene delivery vehicle with potential applications in gene therapy. The developed nanocarrier is capable of delivering any nucleic sequence (up to 8.2 kb) once it is thiolated using the methodology explained in this study. To our knowledge, this represents the first MNP-based nanocarrier capable of delivering nucleic sequences under specific reducing conditions while preserving functionality.

Development of pH-Responsive Polypills via Semi-Solid Extrusion 3D Printing

The low bioavailability of orally administered drugs as a result of the instability in the gastrointestinal tract environment creates significant challenges to developing site-targeted drug delivery systems. This study proposes a novel hydrogel drug carrier using pH-responsive materials assisted with semi-solid extrusion 3D printing technology, enabling site-targeted drug release and customisation of temporal release profiles. The effects of material parameters on the pH-responsive behaviours of printed tablets were analysed thoroughly by investigating the swelling properties under both artificial gastric and intestinal fluids. It has been shown that high swelling rates at either acidic or alkaline conditions can be achieved by adjusting the mass ratio between sodium alginate and carboxymethyl chitosan, enabling site-targeted release. The drug release experiments reveal that gastric drug release can be achieved with a mass ratio of 1:3, whilst a ratio of 3:1 allows for intestinal release. Furthermore, controlled release is realised by tuning the infill density of the printing process. The method proposed in this study can not only significantly improve the bioavailability of oral drugs, but also offer the potential that each component of a compound drug tablet can be released in a controlled manner at a target location.

Designing of SiO2 mesoporous nanoparticles loaded with mometasone furoate for potential nasal drug delivery: Ex vivo evaluation and determination of pro-inflammatory interferon and interleukin mRNA expression

The main objective of the current research work was to synthesize mesoporous silica nanoparticles for controlled delivery of mometasone furoate for potential nasal delivery. The optimized sol-gel method was used for the synthesis of mesoporous silica nanoparticles. Synthesized nanoparticles were processed through Zeta sizer, SEM, TEM, FTIR, TGA, DSC, XRD, and BET analysis for structural characterization. The in vitro dissolution test was performed for the inclusion compound, while the Franz diffusion experiment was performed for permeability of formulation. For the determination of expression levels of anti-inflammatory cytokines IL-4 and IL-5, RNA extraction, reverse transcription, and polymerase chain reaction (RT-PCR) were performed. The MTT assay was also performed to determine cell viability. Synthesized and functionalized mesoporous silica nanoparticles showed controlled release of drugs. FT-IR spectroscopy confirmed the presence of the corresponding functional groups of drugs within mesoporous silica nanoparticles. Zeta sizer and thermal analysis confirmed the delivery system was in nano size and thermally stable. Moreover, a highly porous system was observed during SEM and TEM evaluation, and further it was confirmed by BET analysis. Greater cellular uptake with improved permeability characteristics was also observed. As compared to the crystalline drug, a significant improvement in the dissolution rate was observed. It was concluded that stable mesoporous silica nanoparticles with significant porosity were synthesized, efficiently delivering the loaded drug without any toxic effect.

Euphorbia tirucalli latex loaded polymer nanoparticles: Synthesis, characterization, in vitro release and in vivo antinociceptive action

The encapsulation of drugs in micro and nanocarriers has helped to resolve mechanisms of cellular resistance and decrease drug side effects as well. In this study, poly(D,L-lactide-co-glycolide) (PLGA) was used to encapsulate the Euphol active substance-containing latex from Euphorbia tirucalli (E-latex). The nanoparticles (NP) were prepared using the solvent evaporation method and the physical and chemical properties were evaluated using spectrophotometric techniques. FTIR was used to prove the formation of the ester bond between the E-latex and PLGA-NP. The UV-Vis spectroscopic technique was used to show that more than 75% of the latex was encapsulated; the same technique was used to determine the release profile of the compound at different pH values, as well as determining the speed with which the process occurs through kinetic models, and it was observed that the best adjustments occurred for the Korsmeyer-Peppas model and the Higuchi model. The DLS technique was used to determine the diameter of the particles produced as well as their zeta potential (ZP). The sizes of the particles varied from 497 to 764 nm, and it was observed that the increase in E-latex concentration causes a reduction in the diameter of the NP and an increase in the ZP (-1.44 to -22.7 mV), due to more functional groups from latex film being adsorbed to the NPs surfaces. The thermogravimetric experiments exhibit the glass transition temperatures (Tg) that is appropriate for the use of formulated NPs as a stable drug delivery device before use. The in vivo activity of E-NPs (30 and 100 mg/Kg/p.o.) was tested against carrageenan-induced mechanical hypernociception. The data demonstrated a significantly antinociceptive effect for E-NPs, suggesting that E-latex nanoencapsulation preserved its desired properties.

Developing of SiO2 Nanoshells Loaded with Fluticasone Propionate for Potential Nasal Drug Delivery: Determination of Pro-Inflammatory Cytokines through mRNA Expression

Mesoporous Silica Nanoparticles (MSN) are porous inorganic materials that have been extensively used for drug delivery due to their special qualities, such as biocompatibility, biodegradability, and non-toxicity. MSN is a promising drug delivery system to enhance the efficacy and safety of drug administration in nasal diseases like chronic rhinitis (CR). In this study, we used the sol-gel technique for MSN synthesis and incorporate fluticasone propionate (FP) for intranasal drug administration for the treatment of chronic rhinitis (CR). In order to confirm the particle size, shape, drug release, and compatibility, various instruments were used. MSN was effectively prepared with average sizes ranging between 400 ± 34 nm (mean ± SD) as measured by dynamic light scattering (DLS), while zeta potential verified in all cases their positive charged surface. To investigate MSN features, the Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM), thermal analysis, X-ray diffraction (XRD), and nitrogen adsorption/desorption measurement were used. The loaded compound was submitted to in vitro dissolution tests, and a remarkable dissolution rate improvement was observed compared to the crystalline drug in both pH conditions (1.2 and 7.4 pH). By using an MTT assay cell viability was assessed. The expression levels of the anti-inflammatory cytokines IL-4 and IL-5 were also measured using mRNA extraction from rat blood. Other characterizations like acute toxicity and hemolytic activity were also performed to confirm loaded MSN safety. Loaded MSN was incorporated in nasal spray prepared by using innovator excipients including poloxamer. After this, its nasal spray's physical characteristics were also determined and compared with a commercial product (Ticovate).

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.

Smart Hydrogel Formed by Alginate-g-Poly(N-isopropylacrylamide) and Chitosan through Polyelectrolyte Complexation and Its Controlled Release Properties

Smart hydrogels that can respond to external stimuli such as temperature and pH have attracted tremendous interest for biological and biomedical applications. In this work, we synthesized two alginate-graft-poly(N-isopropylacrylamide) (Alg-g-PNIPAAm) copolymers and aimed to prepare smart hydrogels through formation of polyelectrolyte complex (PEC) between the negatively charged Alg-g-PNIPAAm copolymers and the positively charged chitosan (Cts) in aqueous solutions. The hydrogels were expected to be able to respond to both temperature and pH changes due to the nature of Alg-g-PNIPAAm and chitosan. The hydrogel formation was determined by a test tube inverting method and confirmed by the rheological measurements. The rheological measurements showed that the PEC hydrogels formed at room temperature could be further enhanced by increasing temperature over the lower critical solution temperature (LCST) of PNIPAAm, because PNIPAAm would change from hydrophilic to hydrophobic upon increasing temperature over its LCST, and the hydrophobic interaction between the PNIPAAm segments may act as additional physical crosslinking. The controlled release properties of the hydrogels were studied by using the organic dye rhodamine B (RB) as a model drug at different pH. The PEC hydrogels could sustain the RB release more efficiently at neutral pH. Both low pH and high pH weakened the PEC hydrogels, and resulted in less sustained release profiles. The release kinetics data were found to fit well to the Krosmyer-Peppas power law model. The analysis of the release kinetic parameters obtained by the modelling indicates that the release of RB from the PEC hydrogels followed mechanisms combining diffusion and dissolution of the hydrogels, but the release was mainly governed by diffusion with less dissolution at pH 7.4 when the PEC hydrogels were stronger and stabler than those at pH 5.0 and 10.0. Therefore, the PEC hydrogels are a kind of smart hydrogels holding great potential for drug delivery applications.

Chitosan-based oral colon-specific delivery systems for polyphenols: recent advances and emerging trends

Oral colon-targeted delivery systems (OCDSs) have attracted great attention in the delivery of active compounds targeted to the colon for the treatment of colon and non-colon diseases with the advantages of enhanced efficacy and reduced side effects. Chitosan, the second-most abundant biopolymer next to cellulose, has great biocompatibility, is non-toxic, is sensitive to colonic flora and shows strong adhesion to colonic mucus, making it an ideal biomaterial candidate for the construction of OCDSs. Being rich in functional groups, the chitosan structure is easily modified, both physically and chemically, for the fabrication of delivery systems with diverse geometries, including nanoparticles, microspheres/microparticles, and hydrogels, that are resistant to the harsh environment of the upper gastrointestinal tract (GIT). This review offers a detailed overview of the preparation of chitosan-based delivery systems as the basis for building OCDSs. A variety of natural polyphenols with potent biological activities are used to treat diseases of the colon, or to be metabolized as active ingredients by colonic microorganisms to intervene in remote organ diseases after absorption into the circulation. However, the poor solubility of polyphenols limits their application, and the acidic environment of the upper GIT and various enzymes in the small intestine disrupt their structure and activity. As a result, the development of OCDSs for polyphenols has become an emerging and popular area of current research in the past decade. Thus, the second objective of this review is to systematically summarize the most recent research findings in this area and shed light on the future development of chitosan-based OCDSs for nutritional and biomedical applications.

Rutin-Loaded Stimuli-Responsive Hydrogel for Anti-Inflammation

An active flavonoid compound rutin was incorporated into a guanosine phenylborate hydrogel (GBR) by a stimuli-responsive borate ester linkage for the treatment of inflammatory bowel disease (IBD). The components and morphology of the drug delivery system were characterized by NMR, UV-vis spectroscopy, and AFM. Rheological measurements revealed the required injectability and self-healing ability, which contributed to its application in rectal administration. The cell assays proved the excellent compatibility and safety of the system, and a possible pathway to form multicellular aggregates. In vitro drug-release studies showed that the hydrogel exhibited good stability in physiological medium, and the drug was almost completely released (more than 90 wt % after 24 h of incubation) in acidic pH and excessive ROS-containing medium, realizing the dual-responsive release of pH/ROS. In vivo activities of the GBR hydrogel showed higher therapeutic efficacy than free rutin in a colitis mice model, and it could significantly inhibit overexpressed inflammatory cytokines, including TNF-α and IL-6. Degradation studies of the hydrogel provided further evidence for the safety of its in vivo application. The work provided a simple strategy to prepare a G-quadruplex drug carrier, which was expected to achieve multi-drug delivery.

Loadings of lycopene in emulsion and sodium alginate-K-carrageenan composite systems: Preparation, characterization, bioaccessibility, and kinetics

This research aims to prepare capsules emulsion using gallic acid (GA), dextran (DEX), bovine serum albumin (BSA), sodium alginate, and K-carrageenan (K-Car) as the biological delivery system of lycopene. The stability and bioaccessibility of lycopene were further improved through encapsulation of covalent complex of sodium alginate and K-Car. The molecular weight distribution and secondary structure of the conjugates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR). The storage stability of the emulsion stabilized by conjugates was measured with Turbiscan stability index (TSI) and fluctuation of the particle size. The TSI value of ternary conjugates was 18.7 (37℃) with particle sizes ranging from 208 to 319 nm. Then, the changes of three-dimensional reticulate structures and physical properties of sodium alginate-K were analyzed by scanning electron microscopy (SEM) and TPA. The thermal stability of the sodium alginate-K-Car composite systems was increased compared with sodium alginate. The bioaccessibility of lycopene was significantly improved under the dual embedding of BSA-DEX-GA conjugate emulsion and sodium alginate-K-Car composite systems.

Mechanically tuneable physical nanocomposite hydrogels from polyelectrolyte complex templated silica nanoparticles for anionic therapeutic delivery

Hydrogels have shown great promise for drug delivery and tissue engineering but can be limited in practical applications by poor mechanical performance. The incorporation of polymer grafted silica nanoparticles as chemical or physical crosslinkers in in situ polymerised nanocomposite hydrogels has been widely researched to enhance their mechanical properties. Despite the enhanced mechanical stiffness, tensile strength, and self-healing properties, there remains a need for the development of simpler and modular approaches to obtain nanocomposite hydrogels. Herein, we report a facile protocol for the polyelectrolyte complex (PEC) templated synthesis of organic-inorganic hybrid poly(ethylenimine) functionalised silica nanoparticles (PEI-SiNPs) and their use as multifunctional electrostatic crosslinkers with hyaluronic acid (HA) to form nanocomposite hydrogels. Upon mixing, electrostatic interactions between cationic PEI-SiNPs and anionic HA resulted in the formation of a coacervate nanocomposite hydrogel with enhanced mechanical stiffness that can be tuned by varying the ratios of PEI-SiNPs and HA present. The reversible electrostatic interactions within the hydrogel networks also enabled self-healing and thixotropic properties. The excess positive charge present within the PEI-SiNPs facilitated high loading and retarded the release of the anionic anti-cancer drug methotrexate from the nanocomposite hydrogel. Furthermore, the electrostatic complexation of PEI-SiNP and HA was found to mitigate haemotoxicity concerns associated with the use of high molecular weight PEI. The method presented herein offers a simpler and more versatile strategy for the fabrication of coacervate nanocomposite hydrogels with tuneable mechanical stiffness and self-healing properties for drug delivery applications.

Intelligent hydrogel with both redox and thermo-response based on cellulose nanofiber for controlled drug delivery

The purpose of this study is to develop a hydrogel with temperature and redox response to control drug delivery. However, the strength of temperature sensitive N-isopropylacrylamide (NIPAM) hydrogel is weak. Therefore, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofiber (CNF) is introduced to improve this problem. The compressive strength of hydrogels increased by 360% after CNF addition. Meanwhile, N,N'-bis(acryloyl)cystamine (BACy) is introduced into the hydrogels as a cross-linker, imparting redox responsive properties to the hydrogels. Tumor therapeutic drugs are used as model drugs for in vitro release studies. The drug release rate of hydrogel is regulated by temperature and reducing environment. The maximum cumulative release rate of doxorubicin (DOX) is 39.56%, and the Berberine (BBR) is 99.50% after 60 h. The swelling and transparency of hydrogels showed dramatic changes in the range of 30-40 °C. Cytotoxicity experiments demonstrated that the hydrogel had almost no cytotoxicity.

Chitosan/Alginate Nanoparticles for the Enhanced Oral Antithrombotic Activity of Clam Heparinoid from the Clam Coelomactra antiquata

Chitosan/alginate nanoparticles (DG1-NPs and DG1/Cur-NPs) aiming to enhance the oral antithrombotic activity of clam heparinoid DG1 were prepared by ionotropic pre-gelation. The influence of parameters, such as the concentration of sodium alginate (SA), chitosan (CTS), CaCl2, clam heparinoid DG1, and curcumin (Cur), on the characteristics of the nanoparticles, were investigated. Results indicate that chitosan and alginate can be used as polymer matrices to encapsulate DG1, and nanoparticle characteristics depend on the preparation parameters. Nano-particles should be prepared using 0.6 mg/mL SA, 0.33 mg/mL CaCl2, 0.6 mg/mL CTS, 7.2 mg/mL DG1, and 0.24 mg/mL Cur under vigorous stirring to produce DG1-NPS and DG1/Cur-NPS with small size, high encapsulation efficiency, high loading capacity, and negative zeta potential from approximately −20 to 30 mV. Data from scanning electron microscopy, Fourier-transform infrared spectrometry, and differential scanning calorimetry analyses showed no chemical reaction between DG1, Cur, and the polymers; only physical mixing. Moreover, the drug was loaded in the amorphous phase within the nanoparticle matrix. In the acute pulmonary embolism murine model, DG1-NPs enhanced the oral antithrombotic activity of DG1, but DG1/Cur-NPs did not exhibit higher antithrombotic activity than DG1-NPs. Therefore, the chitosan/alginate nanoparticles enhanced the oral antithrombotic activity of DG1, but curcumin did not further enhance this effect.

Adsorptive removal of organic pollutant methylene blue using polysaccharide-based composite hydrogels

Methylene blue (MB) is categorized as an organic dye (OD) released as effluents after various industrial activities and is one of the most abundant pollutants in the aquatic environment. Significantly, because of its potential toxicity, removing MB from wastewater has been a matter of necessity in recent times. Numerous analytical techniques have been applied, among which polysaccharide-based composite hydrogels appear as the most favorable for MB removal because of their large surface area, excellent mechanical properties, swelling capability, and large-scale production. In this review, the first section gives adequate information about the ODs' adverse effects on the environment and the contribution of polysaccharide-based hydrogels for OD removal, especially MB. Next, various mechanisms such as electrostatic interactions, π-π interactions, hydrogen bonding, hydrophobic interaction, van der Waals force, and coordination interaction involved in the adsorption technique are investigated. The third section extensively describes the MB removal by incorporation of various materials such as monomers, metal oxides, magnetic nanoparticles, and clay into the polysaccharide matrix to produce composite hydrogels. Finally, the current limitations and future perspectives of the polysaccharide-based composite hydrogel techniques are addressed. Overall, this review acknowledged the vital role of polysaccharide-based composite hydrogels for MB adsorption by surveying 110 research articles published in the past five years (2015-2021).

Preparation of pH-sensitive carboxymethyl cellulose/chitosan/alginate hydrogel beads with reticulated shell structure to deliver Bacillus subtilis natto

pH-sensitive hydrogels have been applied in delivering probiotics and drugs. However, pH sensitivity has been found to be contradictory with structural stability in hydrogel preparation. In this work, a novel strategy based on two systems of sodium carboxymethyl cellulose (CMC)/chitosan (CS) and sodium alginate (SA)/calcium chloride was designed to construct a reticulated shell structure stable for 3 h in simulated gastric fluid (pH 1.2) but began to break up at 2 h in simulated intestinal fluid (pH 6.8), exhibiting obvious pH sensitivity. The embedding rate of Bacillus subtilis natto reached to 67.3%, and the sustained release lasted for more than 10 h. It is implicated that the reticulated shell structure has harmoniously balanced the two incompatible properties of pH sensitivity and sustained release of CMC/CS/SA beads.

Development and optimization of tibezonium iodide and lignocaine hydrochloride containing novel mucoadhesive buccal tablets: A pharmacokinetic investigation among healthy humans

OBJECTIVE

It is clinically important to deliver sustained-release mucoadhesive dosage of local anesthetic and antimicrobial agent for pain control. The current study aimed to develop and evaluate chitosan (CHI) based buccal mucoadhesive delivery for local release of tibezonium iodide (TBN) and lignocaine hydrochloride (LGN).

METHODS

Direct compression technique was employed, aided by other mucoadhesive polymers like hydroxypropylmethylcellulose (HPMC) and sodium alginate (SA) and evaluated for physicochemical and in vivo character.

RESULTS

Fourier transform infrared spectral analysis (FTIR), powdered X-ray diffraction (XRPD), and differential scanning calorimetry (DSC) absence of physical interaction between ingredients. The physical parameters complied with USP specifications for all formulations. Optimum swellability (551.9%) was offered from formulation TL15, containing 30% SA. Highest ex vivo mucoadhesive strength (24.79 g) and time (18.39 h) was found with TL8. Formulation TL8 also exhibited maximum in vivo residence time (11.37 h). Almost complete drug release at 6 h was possessed by formulation TL5 (HPMC and CHI, 20% each) for TBN (99.98%) and LGN (99.06%). The optimized formulation TL5 exhibited dosage stability up to 6 months at 75% relative humidity and retained drug contents. TL5 was well tolerated by the volunteers with no inflammation, pain or irritation found. Almost 73% of volunteers reported an increase in salivary secretion. The first-order salivary C_max of TBN and LGN were found as 16.02 and 7.80 µg/mL within 4 h, respectively.

CONCLUSION

Therefore, the sustained release mucoadhesive dosage form of TBN and LGN can be an effective and alternative option to conventional delivery.

Development of a Polysaccharide-Based Hydrogel Drug Delivery System (DDS): An Update

Delivering a drug to the target site with minimal-to-no off-target cytotoxicity is the major determinant for the success of disease therapy. While the therapeutic efficacy and cytotoxicity of the drug play the main roles, the use of a suitable drug delivery system (DDS) is important to protect the drug along the administration route and release it at the desired target site. Polysaccharides have been extensively studied as a biomaterial for DDS development due to their high biocompatibility. More usefully, polysaccharides can be crosslinked with various molecules such as micro/nanoparticles and hydrogels to form a modified DDS. According to IUPAC, hydrogel is defined as the structure and processing of sols, gels, networks and inorganic–organic hybrids. This 3D network which often consists of a hydrophilic polymer can drastically improve the physical and chemical properties of DDS to increase the biodegradability and bioavailability of the carrier drugs. The advancement of nanotechnology also allows the construction of hydrogel DDS with enhanced functionalities such as stimuli-responsiveness, target specificity, sustained drug release, and therapeutic efficacy. This review provides a current update on the use of hydrogel DDS derived from polysaccharide-based materials in delivering various therapeutic molecules and drugs. We also highlighted the factors that affect the efficacy of these DDS and the current challenges of developing them for clinical use.

Evaluating Release Kinetics from Alginate Beads Coated with Polyelectrolyte Layers for Sustained Drug Delivery

Current approaches in stem cell-based bone tissue engineering require a release of bioactive compounds over up to 2 weeks. This study presents a polyelectrolyte-layered system featuring sustained release of water-soluble drugs with decreased burst release. The bioactive compounds adenosine 5'-triphosphate (ATP), suramin, and A740003 (a less water-soluble purinergic receptor ligand) were incorporated into alginate hydrogel beads subsequently layered with different polyelectrolytes (chitosan, poly(allyl amine), alginate, or lignosulfonate). Drug release into aqueous medium was monitored over 14 days and evaluated using Korsmeyer-Peppas, Peppas-Sahlin, Weibull models, and a Langmuir-like "Two-Stage" model. Release kinetics strongly depended on both the drug and the polyelectrolyte system. For ATP, five alternating layers of poly(allyl amine) and alginate proved to be most effective in sustaining the release. Release of suramin could be prolonged best with lignosulfonate as polyanion. A740003 showed prolonged release even without layering. Applying polyelectrolyte layers significantly slowed down the burst release. Release curves could be best described with the Langmuir-like model.

Floating chitosan-alginate microspheres loaded with chlorantraniliprole effectively control Chilo suppressalis (Walker) and Sesamia inferens (Walker) in rice fields

Striped rice stem borer, Chilo suppressalis (Walker) and pink stem borer, Sesamia inferens (Walker) are two important pests, causing substantial yield loss in rice production. Application of conventional synthetic pesticides, such as suspension concentrates and water-dispersible granules, is a primary method for control of the two pests. Due to the flow of water in rice field, spray drift, and soil adsorption, applied such pesticides are often out of the target, resulting in low control efficacy, potential contamination of soil or surface water, and also threat to human health. Thus, there is an urgent need for developing environmentally friendly and highly targeted pesticide formulations to meet the challenges. The present study synthesized chlorantraniliprole loaded chitosan-alginate floating hydrogel microspheres (CCAM) through physical embedding, ionic crosslinking, and incorporation of citronellol as an oil phase. The morphology, particle size, entrapment efficiency, loading capacity, in vitro slow-release kinetics, and floating ability of the CCAM were tested in laboratory conditions. The CCAM and two commercial formulations (suspended and granulated) of chlorantraniliprole were respectively evaluated in two rice fields located in two provinces of China. The CCAM was able to float on the surface of rice field, gather around rice stems, and slowly release chlorantraniliprole, which resulted in significantly higher concentrations of chlorantraniliprole in rice stems and leaves for a prolonged time than suspended and granulated controls. The application of CCAM provided an on-target control of both striped stem borer and pink stem borer. Furthermore, CCAM application had very low residue of chlorantraniliprole in soils. As far as is known, this is the first report of chlorantraniliprole loaded on chitosan-alginate floating hydrogel microspheres for rice stem borer control. Our results indicate that the synthesized CCAM could potentially be used as a controlled-release product for effective control of the two rice pests, while reducing the residual chlorantraniliprole in the soil and avoiding pesticide drift.

Potential Applications of Chitosan-Based Nanomaterials to Surpass the Gastrointestinal Physiological Obstacles and Enhance the Intestinal Drug Absorption

The small intestine provides the major site for the absorption of numerous orally administered drugs. However, before reaching to the systemic circulation to exert beneficial pharmacological activities, the oral drug delivery is hindered by poor absorption/metabolic instability of the drugs in gastrointestinal (GI) tract and the presence of the mucus layer overlying intestinal epithelium. Therefore, a polymeric drug delivery system has emerged as a robust approach to enhance oral drug bioavailability and intestinal drug absorption. Chitosan, a cationic polymer derived from chitin, and its derivatives have received remarkable attention to serve as a promising drug carrier, chiefly owing to their versatile, biocompatible, biodegradable, and non-toxic properties. Several types of chitosan-based drug delivery systems have been developed, including chemical modification, conjugates, capsules, and hybrids. They have been shown to be effective in improving intestinal assimilation of several types of drugs, e.g., antidiabetic, anticancer, antimicrobial, and anti-inflammatory drugs. In this review, the physiological challenges affecting intestinal drug absorption and the effects of chitosan on those parameters impacting on oral bioavailability are summarized. More appreciably, types of chitosan-based nanomaterials enhancing intestinal drug absorption and their mechanisms, as well as potential applications in diabetes, cancers, infections, and inflammation, are highlighted. The future perspective of chitosan applications is also discussed.

Recent advances in the production of biomedical systems based on polyhydroxyalkanoates and exopolysaccharides

In recent years, growing attention has been devoted to naturally occurring biological macromolecules and their ensuing application in agriculture, cosmetics, food and pharmaceutical industries. They inherently have antigenicity, low immunogenicity, excellent biocompatibility and cytocompatibility, which are ideal properties for the design of biomedical devices, especially for the controlled delivery of active ingredients in the most diverse contexts. Furthermore, these properties can be modulated by chemical modification via the incorporation of other (macro)molecules in a random or controlled way, aiming at improving their functionality for each specific application. Among the wide variety of natural polymers, microbial polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPS) are often considered for the development of original biomaterials due to their unique physicochemical and biological features. Here, we aim to fullfil a gap on the present associated literature, bringing an up-to-date overview of ongoing research strategies that make use of PHAs (poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyvalerate), poly (3-hydroxyoctanoate), poly(3-hydroxypropionate), poly (3-hydroxyhexanoate-co-3-hydroxyoctanoate), and poly (3-hydroxybutyrate-co-3-hydroxyhexanoate)) and EPS (bacterial cellulose, alginates, curdlan, pullulan, xanthan gum, dextran, hyaluronan, and schizophyllan) as sources of interesting and versatile biomaterials. For the first time, a monograph addressing the properties, pros and cons, status, challenges, and recent progresses regarding the application of these two important classes of biopolymers in biomedicine is presented.

All-polysaccharide hydrogels for drug delivery applications: Tunable chitosan beads surfaces via physical or chemical interactions, using oxidized pullulan

The present work reports a versatile approach to the manufacture of chitosan beads with tunable pore size and targeted properties. To achieve this, the as prepared chitosan beads were allowed to interact with aqueous solutions of two types of oxidized pullulan derivatives. Depending on the functional groups present on the pullulan structure after oxidation, i.e., carboxyl or aldehyde, covalent or physical hybrid hydrogels could be prepared. The attachment of oxidized pullulan onto chitosan structure was checked by FTIR, RMN, XPS and thermal analysis. The morphology of the hybrid structures was evaluated by using Scanning Electron Microscopy (SEM). After structural evaluations, all the prepared hydrogels were characterized by means of dynamic vapor sorption and swelling degree studies, exhibiting a Case-II swelling mechanism. Drug model compounds, such as ibuprofen, bacitracin and neomycin were used for drug loading and release assays, proving high drug loading capacity and tunable release behavior. Drug loaded beads exhibited antibacterial activity and hemocompatibility experiments indicated no coagulation phenomena.

Biomaterials for protein delivery for complex tissue healing responses

Tissue repair requires a complex cascade of events mediated by a variety of cells, proteins, and matrix molecules; however, the healing cascade can be easily disrupted by numerous factors, resulting in impaired tissue regeneration. Recent advances in biomaterials for tissue regeneration have increased the ability to tailor the delivery of proteins and other biomolecules to injury sites to restore normal healing cascades and stimulate robust tissue repair. In this review, we discuss the evolution of the field toward creating biomaterials that precisely control protein delivery to stimulate tissue regeneration, with a focus on addressing complex and dynamic injury environments. We highlight biomaterials that leverage different mechanisms to deliver and present proteins involved in healing cascades, tissue targeting and mimicking strategies, materials that can be triggered by environmental cues, and integrated strategies that combine multiple biomaterial properties to improve protein delivery. Improvements in biomaterial design to address complex injury environments will expand our understanding of both normal and aberrant tissue repair processes and ultimately provide a better standard of patient care.

Chitosan coated pH-responsive metal-polyphenol delivery platform for melanoma chemotherapy

The safe and effective drug delivery system is important for cancer therapy. Here in, we first constructed a delivery system Cabazitaxel(Cab)@MPN/CS between metal-polyphenol (MPN) and chitosan (CS) to deliver Cab for melanoma therapy. The preparation process is simple, green, and controllable. After introducing CS coating, the drug loading was improved from 7.56 % to 9.28 %. Cab@MPN/CS NPs released Cab continuously under acid tumor microenvironment. The zeta potential of Cab@MPN/CS NPs could be controlled by changing the ratio of Cab@MPN and CS solutions. The positively charged Cab@MPN/CS accelerate B16F10 cell internalization. After internalized, Cab@MPN/CS NPs could escape from lysosomes via the proton sponge effect. The permeability of CS promotes the penetration of Cab@MPN/CS to the deeper B16F10 tumor spheroids. In vivo results showed that Cab@MPN/CS NPs have a longer retention time in tumor tissues and significantly inhibit tumor growth by up-regulating TUNEL expression and down-regulating KI67 and CD31 expression. Thus, this delivery system provides a promising strategy for the tumor therapy in clinic.

Fabrication of nanostructured multi-unit vehicle for intestinal-specific delivery and controlled release of peptide

An oral multi-unit delivery system was developed by incorporating the nanoparticle (NP) into the nanofiber mat and its efficiency for intestinal-specific delivery and controlled release of a peptide (insulin) was investigated. Initially, the influence of deacetylation degree (DD) of chitosan and ionic gelation methods on the properties of NPs was studied. High DD (95%) chitosan was attributed to higher encapsulation efficiency and stability when crosslinked with polyanion tripolyphosphate. Subsequently, the multi-unit system was fabricated using a pH-sensitive polymer (sodium alginate) as the coating layer to further encapsulate the NP. Fiber mat with an average diameter of 481 ± 47 nm could significantly decrease the burst release of insulin in acidic condition and release most amount of insulin (>60%) in the simulated intestinal medium. Furthermore, the encapsulated peptide remained in good integrity. This multi-unit carrier provides the better-designed vehicle for intestinal-specific delivery and controlled release of the peptide.

Controlled release evaluation of paracetamol loaded amine functionalized mesoporous silica KCC1 compared to microcrystalline cellulose based tablets

In the pharmaceutical manufacturing, drug release behavior development is remained as one of the main challenges to improve the drug effectiveness. Recently, more focus has been done on using mesoporous silica materials as drug carriers for prolonged and superior control of drug release in human body. In this study, release behavior of paracetamol is developed using drug-loaded KCC-1-NH2 mesoporous silica, based on direct compaction method for preparation of tablets. The purpose of this study is to investigate the utilizing of pure KCC-1 mesoporous silica (KCC-1) and amino functionalized KCC-1 (KCC-1-NH2) as drug carriers in oral solid dosage formulations compared to common excipient, microcrystalline cellulose (MCC), to improve the control of drug release rate by manipulating surface chemistry of the carrier. Different formulations of KCC-1 and KCC-NH2 are designed to investigate the effect of functionalized mesoporous silica as carrier on drug controlled-release rate. The results displayed the remarkable effect of KCC-1-NH2 on drug controlled-release in comparison with the formulation containing pure KCC-1 and formulation including MCC as reference materials. The pure KCC-1 and KCC-1-NH2 are characterized using different evaluation methods such as FTIR, SEM, TEM and N2 adsorption analysis.

Facile preparation of stretchable and self-healable conductive hydrogels based on sodium alginate/polypyrrole nanofibers for use in flexible supercapacitor and strain sensors

A series of multifunctional conductive hydrogels (denoted as SA-B-DAPPy) is developed by combining sodium alginate (SA) and dopamine functionalized polypyrrole (DAPPy) nanofibers with borax as a cross-linking agent. By modulation of the DAPPy weight ratio to 3.5 wt%, the conductivity of the hydrogel can reach a high value of 1.33 ± 0.012 S/m. Both borate interactions and hydrogen bonds within hydrogel frameworks can account for the satisfactory stretchability (more than 800%) and instantaneous self-healing ability. More significantly, the SA-B-DAPPy hydorgels can be easily fabricated as electrode component in the symmetric supercapacitor with SA-B-DAPPy//SA-B//SA-B-DAPPy configuration. Due to the self-healing of the electrode/electrolyte interface, the obtained all-in-one device can deliver superior areal specific capacitance of 587 mF/cm² at current density of 1.0 mA/cm², high energy density of 52.18 μWh/cm² at power density of 800 μW/cm², good capacitance retention of 80% after 2000 cycles, as well as integration characteristics. Furthermore, on account of high conductivity, a thin SA-B-DAPPy hydrogel film can be fabricated into the motion sensor to detect and distinguish various human movements. The sensor exhibits high gauge factor (GF) up to 10.23, and stable, repeatable response signals, which permit supersensitive for monitoring large-scale joints motions and subtle muscle movements.

Synthesis and characterization of novel organo-hydrogel based agar, glycerol and peppermint oil as a natural drug carrier/release material

The very recent Covid-19 pandemic has made the need to understand biocompatible polymers as support material in drug delivery systems and controlled release clearer, especially for organo-hydrogels. This study aims to synthesize various new polymeric materials called gels, hydrogels, and organo-hydrogels according to the monomer used and to investigate their use as drug release systems. The agar-glycerol (AG) pair was used to synthesize the polymers, N, N, methylene bisacrylamide (MBA, m) and glutaraldehyde (GA, g) were used as cross-linkers and peppermint oil (PmO) was included to obtain the organo-hydrogels. Therefore, one AG gel and two p (AG-m) and p (GA-g) hydrogels were synthesized within the scope of the study. Six different organo-hydrogels based on p(AG-m-PmO) or p (AG-g-PmO) were also synthesized by varying the amount of peppermint oil. Paracetamol and carboplatin were selected as the sample drugs. Synthesized gels, hydrogels and organo-hydrogels were characterized by FTIR and SEM analysis. Additionally, swelling behaviors of the synthesized gels were investigated in different media (ID water, tap water, ethanol, acetone, ethanol/ID water (1:1), acetone/ID water (1:1) and gasoline) and at different pHs. Moreover, it was determined that organo-hydrogels were blood compatible and had antioxidant properties based on hemolysis, blood clotting and antioxidant analysis. Therefore, the release of paracetamol (a known antipyretic-painkiller, recommended and used in the treatment of Covid-19) and carboplatin (widely used in cancer treatment) were studied. Evidently, as the amount of PMO oil increases, the -OH groups in organo-hydrogels will increase and the chemical and physical bonding rates will increase; therefore it was observed that increasing peppermint oil in the organo-hydrogels structure to 0.3 mL stimulated the release of the drugs. For instance, maximum paracetamol release amount from p(AG-g-PmO) and p(AG-m-PmO) organo-hydrogels was calculated to be 72.3% at pH 7.4 and 69.8% at pH 2.0, respectively. The maximum carboplatin release amount from p(AG-g-PmO) and p(AG-m-PmO) organo-hydrogels was calculated to be 99.7% at pH 7.4 and 100% at pH 7.4, respectively. It was concluded that the synthesized organo-hydrogels might easily be used as drug carrier and controlled drug release materials.

Preparation and characterization of curcumin solid dispersion using HPMC

Curcumin solid dispersions were prepared using hydroxypropyl methylcellulose (HPMC) to enhance water solubility of curcumin. The particle size of curcumin solid dispersions was in range from 371 to 528 nm and particles were shaped as spherical with wrinkles. The encapsulation efficiency was over 93% for all samples, and water solubility of curcumin was significantly improved to 238 µg/mL when the ratio of curcumin to HPMC was 20:80. The results of X-ray diffraction, differential scanning calorimeter, and Fourier transform infrared spectroscopy showed that crystalline form of curcumin changed to amorphous form. Curcumin solid dispersions showed improved dissolution behavior compared to pure curcumin and the curcumin release kinetic studies were applied to find best-fitting model. This study showed a great potential of solid dispersion using HPMC as curcumin delivery system with improved water solubility and oral absorption. PRACTICAL APPLICATION: Curcumin has limited applications in the food industry because of low water solubility. Dongoh water-soluble curcumin (DW-CURs) were prepared by solid dispersion method with HPMC. Our results indicated that curcumin solid dispersions improved the water solubility of curcumin and showed a sustained release, demonstrating its possibility of body application. Therefore, DW-CURs are a promising formulation for application as a functional ingredient in the food industry.