Development of novel pH-sensitive nanoparticles loaded hydrogel for transdermal drug delivery

Citric acid cross-linked pomegranate peel extract-loaded pH-responsive β-cyclodextrin/carboxymethyl tapioca starch hydrogel film for diabetic wound healing

Pomegranate peel extract (PPE) hydrogel films filled with citric acid (CA) and β-cyclodextrin-carboxymethyl tapioca starch (CMS) were designed mainly to prevent wound infections and speed up the healing process. FTIR and NMR studies corroborated the carboxymethylation of neat tapioca starch (NS). CMS exhibited superior swelling behavior than NS. The amount of CA and β-CD controlled the physicochemical parameters of developed PPE/CA/β-CD/CMS films. Optimized film (OF) exhibited acceptable swellability, wound fluid absorptivity, water vapor transmission rate, water contact angle, and mechanical properties. Biodegradable, biocompatible, and antibacterial films exhibited pH dependence in the release of ellagic acid for up to 24 h. In mice model, PPE/CA/β-CD/CMS hydrogel film treatment showed promising wound healing effects, including increased collagen deposition, reduced inflammation, activation of the Wingless-related integration site (wnt) pathway leading to cell division, proliferation, and migration to the wound site. The expression of the WNT3A gene did not show any significant differences among all the studied groups. Developed PPE-loaded CA/β-CD/CMS film promoted wound healing by epithelialization, granulation tissue thickness, collagen deposition, and angiogenesis, hence could be recommended as a biodegradable and antibacterial hydrogel platform to improve the cell proliferation during the healing of diabetic wounds.

Drug-eluting contact lenses: Progress, challenges, and prospects

Topical ophthalmic solutions (eye drops) are becoming increasingly popular in treating and preventing ocular diseases for their safety, noninvasiveness, and ease of handling. However, the static and dynamic barriers of eyes cause the extremely low bioavailability (<5%) of eye drops, making ocular therapy challenging. Thus, drug-eluting corneal contact lenses (DECLs) have been intensively investigated as a drug delivery device for their attractive properties, such as sustained drug release and improved bioavailability. In order to promote the clinical application of DECLs, multiple aspects, i.e., drug release and penetration, safety, and biocompatibility, of these drug delivery systems were thoroughly examined. In this review, we systematically discussed advances in DECLs, including types of preparation materials, drug-loading strategies, drug release mechanisms, strategies for penetrating ocular barriers, in vitro and in vivo drug delivery and penetration detection, safety, and biocompatibility validation methods, as well as challenges and future perspectives.

Development of pH-Sensitive Nanoparticle Incorporated into Dissolving Microarray Patch for Selective Delivery of Methotrexate

PURPOSE

Rheumatoid arthritis (RA) is a systemic autoimmune disease that attacks human joints. Methotrexate (MTX), as one the most effective medications to treat RA, has limitations when administered either orally or by injection. To overcome this limitation, we formulated MTX through a smart nanoparticle (SNP) combined with dissolving microarray patch (DMAP) to achieve selective-targeted delivery of RA.

METHODS

SNP was made using the combination of polyethylene glycol (PEG) and polycaprolactone (PCL) polymers, while DMAP was made using the combination of hyaluronic acid and polyvinylpyrrolidone K-30. SNP-DMAP was then evaluated for its mechanical and chemical characteristics, ex vivo permeation test, in vivo pharmacokinetic study, hemolysis, and hen's egg test-chorioallantoic membrane (HET-CAM) test.

RESULT

The results showed that the characteristics of the SNP-DMAP-MTX formulas meet the requirements for transdermal delivery, with the particle size of 189.09 ±12.30 nm and absorption efficiency of 65.40 ± 5.0%. The hemolysis and HET-CAM testing indicate that this formula was non-toxic and non-irritating. Ex vivo permeation shows a concentration of 51.50 ± 3.20 µg/mL of SNP-DMAP-MTX in PBS pH 5.0. The pharmacokinetic profile of SNP-DMAP-MTX showed selectivity and sustained release compared with oral and DMAP-MTX with values of t1/2 (4.88 ± 0 h), Tmax (8 ± 0 h), Cmax (0.50 ± 0.04 μg/mL), AUC (3.15 ± 0.54 μg/mL.h), and mean residence time (MRT) (9.13 ± 0 h).

CONCLUSION

The developed SNP-DMAP-MTX has been proven to deliver MTX transdermal and selectively at the RA site, potentially avoiding conventional MTX side effects and enhancing the effectiveness of RA therapy.

Chiral Supramolecular Hydrogel Enhanced Transdermal Delivery of Sodium Aescinate to Modulate M1 Macrophage Polarization Against Lymphedema

Sodium aescinate (SA) shows great potential for treating lymphedema since it can regulate the expression of cytokines in M1 macrophages, however, it is commonly administered intravenously in clinical practice and often accompanied by severe toxic side effects and short metabolic cycles. Herein, SA-loaded chiral supramolecular hydrogels are prepared to prove the curative effects of SA on lymphedema and enhance its safety and transdermal transmission efficiency. In vitro studies demonstrate that SA- loaded chiral supramolecular hydrogels can modulate local immune responses by inhibiting M1 macrophage polarization. Typically, these chiral hydrogels can significantly increase the permeability of SA with good biocompatibility due to the high enantioselectivity between chiral gelators and stratum corneum and L-type hydrogels are found to have preferable drug penetration over D-type hydrogels. In vivo studies show that topical delivery of SA via chiral hydrogels results in dramatic therapeutic effects on lymphedema. Specifically, it can downregulate the level of inflammatory cytokines, reduce the development of fibrosis, and promote the regeneration of lymphatic vessels. This study initiates the use of SA for lymphedema treatment and for the creation of an effective chiral biological platform for improved topical administration.

Advances in Transdermal Drug Delivery Systems: A Bibliometric and Patent Analysis

Transdermal drug delivery systems have become an intriguing research topic in healthcare technology and one of the most frequently developed pharmaceutical products in the global market. In recent years, researchers and pharmaceutical companies have made significant progress in developing new solutions in the field. This study sheds light on current trends, collaboration patterns, research hotspots, and emerging frontiers of transdermal drug delivery. Herein, a bibliometric and patent analysis of data recovered from Scopus and The Lens databases, respectively, is reported over the last 20 years. From 2000 to 2022, the annual global publications increased from 131 in 2000 to 659 in 2022. Researchers in the United States, China, and India produced the highest number of publications. Likewise, most patent applications have been filed in the USA, China, and Europe. The recovered patents are 7275, grouped into 2997 patent families, of which 314 were granted. This study could support the work of decision-makers, scientific managers, or scientists to create new business opportunities or save money, time, and intellectual capital, thereby defining when a research or technology project should be a priority or not.

Development of chitosan-hyaluronic acid based hydrogel for local delivery of doxycycline hyclate in an ex vivo skin infection model

Doxycycline hyclate (DOXY) is a tetracycline derivative known as the broad-spectrum bacteriostatic drug. DOXY has been suggested as the first-line antibiotic for diabetic foot ulcers (DFU). Unfortunately, the long-term availability of DOXY in both oral and conventional topical dosage forms reduces its therapeutic effectiveness, which is closely linked to gastrointestinal side effects and acute pain during therapy, as well as uncontrolled DOXY release at the wound site. To address these shortcomings, we present for the first time a DOXY hydrogel system (DHs) built on crosslinks between carboxymethyl chitosan (CMC) and aldehyde hyaluronic acid (AHA). Three formulations of DHs were developed with different ratios of CMC and AHA, consisting of F1 (3:7, w/w), F2 (5:5, w/w), and F3 (7:3, w/w). Viscosity, rheology, gel strength, pH, swelling, gel fraction, wettability, stability, in vitro drug release, ex vivo antibacterial, and dermatokinetic studies were used to evaluate the DHs. According to the in vitro release study, up to 85% of DOXY was released from DHs via the Fickian diffusion mechanism in the Korsmeyer-Peppas model (n < 0.45), which provides controlled drug delivery. Because of its excellent physicochemical characteristics, F2 was chosen as the best DHs formulation in this study. Essentially, the optimum DHs formulation could greatly improve DOXY's ex vivo dermatokinetic profile while also providing excellent antibacterial activity. As a consequence, this study had promising outcome as a proof of concept for increasing the efficacy of DOXY in clinical therapy. Further extensive in vivo studies are required to evaluate the efficacy of this approach.

In vitro and in vivo characterization of Miconazole Nitrate loaded transethosomes for the treatment of Cutaneous Candidiasis

This study aimed to fabricate Miconazole Nitrate transethosomes (MCZN TESs) embedded in chitosan-based gel for the topical treatment of Cutaneous Candidiasis. A thin film hydration method was employed to formulate MCZN TESs. The prepared MCZN TESs were optimized and analyzed for their physicochemical properties including particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (%EE), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), deformability, and Transmission electron microscopy (TEM). In vitro release, skin permeation and deposition, skin irritation, antifungal assay, and in vivo efficacy against infected rats were evaluated. The optimized MCZN TESs showed PS of 224.8 ± 5.1 nm, ZP 21.1 ± 1.10 mV, PDI 0.207 ± 0.009, and % EE 94.12 ± 0.101 % with sustained drug release profile. Moreover, MCZN TESs Gel exhibited desirable pH, spreadability, and viscosity. Notably, the penetration and deposition capabilities of MCZN TESs Gel showed a 4-fold enhancement compared to MCZN TESs. Importantly, in vitro antifungal assay elaborated MCZN TESs Gel anti-fungal activity was 2.38-fold more compared to MCZN Gel. In vivo, studies showed a 1.5 times reduction in the duration of treatment MCZN TESs Gel treated animal group. Therefore, studies demonstrated that MCZN TESs could be a suitable drug delivery system with higher penetration and good antifungal potential.

Methyl Canthin-6-one-2-carboxylate Restrains the Migration/Invasion Properties of Fibroblast-like Synoviocytes by Suppressing the Hippo/YAP Signaling Pathway

Rheumatoid arthritis (RA) is an inflammatory condition that causes severe cartilage degradation and synovial damage in the joints with multiple systemic implications. Previous studies have revealed that fibroblast-like synoviocytes (FLSs) play a pivotal role in the pathogenesis of RA. The appropriate regulation of FLS function is an efficient approach for the treatment of this disease. In the present study, we explored the effects of methyl canthin-6-one-2-carboxylate (Cant), a novel canthin-6-one alkaloid, on the function of FLSs. Our data showed that exposure to Cant significantly suppressed RA-FLS migration and invasion properties in a dose-dependent manner. Meanwhile, pre-treatment with Cant also had an inhibitory effect on the release of several pro-inflammatory cytokines, including IL-6 and IL-1β, as well as the production of MMP1 and MMP3, which are important mediators of FLS invasion. In further mechanistic studies, we found that Cant had an inhibitory effect on the Hippo/YAP signaling pathway. Treatment with Cant suppressed YAP expression and phosphorylation on serine 127 and serine 397 while enhancing LATS1 and MST1 levels, both being important upstream regulators of YAP. Moreover, YAP-specific siRNA or YAP inhibition significantly inhibited wound healing as well as the migration and invasion rate of FLS cells, an impact similar to Cant treatment. Meanwhile, the over-expression of YAP significantly reversed the Cant-induced decline in RA-FLS cell migration and invasion, indicating that YAP was required in the inhibitory effect of Cant on the migration and invasion of RA-FLS cells. Additionally, supplementation of MMP1, but not MMP3, in culture supernatants significantly reversed the inhibitory effect of Cant on RA-FLS cell invasion. Our data collectively demonstrated that Cant may suppress RA-FLS migration and invasion by inhibiting the production of MMP1 via inhibiting the YAP signaling pathway, suggesting a potential of Cant for the further development of anti-RA drugs.

Thermo-Responsive Hydrogels Encapsulating Targeted Core-Shell Nanoparticles as Injectable Drug Delivery Systems

As therapeutic agents that allow for minimally invasive administration, injectable biomaterials stand out as effective tools with tunable properties. Furthermore, hydrogels with responsive features present potential platforms for delivering therapeutics to desired sites in the body. Herein, temperature-responsive hydrogel scaffolds with embedded targeted nanoparticles were utilized to achieve controlled drug delivery via local drug administration. Poly(N-isopropylacrylamide) (pNIPAM) hydrogels, prepared with an ethylene-glycol-based cross-linker, demonstrated thermo-sensitive gelation ability upon injection into environments at body temperature. This hydrogel network was engineered to provide a slow and controlled drug release profile by being incorporated with curcumin-loaded nanoparticles bearing high encapsulation efficiency. A core (alginate)-shell (chitosan) nanoparticle design was preferred to ensure the stability of the drug molecules encapsulated in the core and to provide slower drug release. Nanoparticle-embedded hydrogels were shown to release curcumin at least four times slower compared to the free nanoparticle itself and to possess high water uptake capacity and more mechanically stable viscoelastic behavior. Moreover, this therapy has the potential to specifically address tumor tissues over-expressing folate receptors like ovaries, as the nanoparticles target the receptors by folic acid conjugation to the periphery. Together with its temperature-driven injectability, it can be concluded that this hydrogel scaffold with drug-loaded and embedded folate-targeting nanoparticles would provide effective therapy for tumor tissues accessible via minimally invasive routes and be beneficial for post-operative drug administration after tumor resection.

Microemulsion-Based Keratin-Chitosan Gel for Improvement of Skin Permeation/Retention and Activity of Curcumin

Curcumin (Cur) is a kind of polyphenol with a variety of topical pharmacological properties including antioxidant, analgesic and anti-inflammatory activities. However, its low water solubility and poor skin bioavailability limit its effectiveness. In the current study, we aimed to develop microemulsion-based keratin-chitosan gel for the improvement of the topical activity of Cur. The curcumin-loaded microemulsion (CME) was formulated and then loaded into the keratin-chitosan (KCS) gel to form the CME-KCS gel. The formulated CME-KCS gel was evaluated for its characterization, in vitro release, in vitro skin permeation and in vivo activity. The results showed that the developed CME-KCS gel had an orange-yellow and gel-like appearance. The particle size and zeta potential of the CME-KCS gel were 186.45 ± 0.75 nm and 9.42 ± 0.86 mV, respectively. The CME-KCS gel showed desirable viscoelasticity, spreadability, bioadhesion and controlled drug release, which was suitable for topical application. The in vitro skin permeation and retention study showed that the CME-KCS gel had better in vitro skin penetration than the Cur solution and achieved maximum skin drug retention (3.75 ± 0.24 μg/cm²). In vivo experimental results confirmed that the CME-KCS gel was more effective than curcumin-loaded microemulsion (Cur-ME) in analgesic and anti-inflammatory activities. In addition, the CME-KCS gel did not cause any erythema or edema based on a mice skin irritation test. These findings indicated that the developed CME-KCS gel could improve the skin penetration and retention of Cur and could become a promising formulation for topical delivery to treat local diseases.

A pH-sensitive drug delivery using biodegradable succinoglycan/chitosan hydrogels with synergistic antibacterial activity

Since succinoglycan (SG) produced by Sinorhizobium meliloti is an anionic polysaccharide having substituents such as succinate and pyruvate groups, a polyelectrolyte composite hydrogel can be made together with chitosan (CS), a cationic polysaccharide. We fabricated polyelectrolyte SG/CS hydrogels using the semi-dissolving acidified sol-gel transfer (SD-A-SGT) method. The hydrogel showed optimized mechanical strength and thermal stability at an SG:CS weight ratio of 3:1. This optimized SG/CS hydrogel exhibited a high compressive stress of 497.67 kPa at 84.65 % strain and a high tensile strength of 9.14 kPa when stretched to 43.73 %. Additionally, this SG/CS hydrogel showed a pH-controlled drug release pattern for 5-fluorouracil (5-FU), where a change from pH 7.4 to 2.0 increased the release from 60 % to 94 %. In addition, this SG/CS hydrogel not only showed a cell viability of 97.57 %, but also showed synergistic antibacterial activity of 97.75 % and 96.76 % against S. aureus and E. coli, respectively. These results indicate the potential of this hydrogel as a biocompatible and biodegradable hydrogel material for wound healing, tissue engineering, and drug release systems.

Capsaicin-loaded alginate nanoparticles embedded polycaprolactone-chitosan nanofibers as a controlled drug delivery nanoplatform for anticancer activity

Nanocarrier-based drug delivery systems have been designed into various structures that can effectively prevent cancer progression and improve the therapeutic cancer index. However, most of these delivery systems are designed to be simple nanostructures with several limitations, including low stability and burst drug release features. A nano-in-nano delivery technique is explored to address the aforementioned concerns. Accordingly, this study investigated the release behavior of a novel nanoparticles-in-nanofibers delivery system composed of capsaicin-loaded alginate nanoparticles embedded in polycaprolactone-chitosan nanofiber mats. First, alginate nanoparticles were prepared with different concentrations of cationic gemini surfactant and using nanoemulsion templates. The optimized formulation of alginate nanoparticles was utilized for loading capsaicin and exhibited a diameter of 19.42 ± 1.8 nm and encapsulation efficiency of 98.7 % ± 0.6 %. Likewise, blend polycaprolactone-chitosan nanofibers were prepared with different blend ratios of their solutions (i.e., 100:0, 80:20, 60:40) by electrospinning method. After the characterization of electrospun mats, the optimal nanofibers were employed for embedding capsaicin-loaded alginate nanoparticles. Our findings revealed that embedding capsaicin-loaded alginate nanoparticles in polycaprolactone-chitosan nanofibers, prolonged capsaicin release from 120 h to more than 500 h. Furthermore, the results of in vitro analysis demonstrated that the designed nanoplatform could effectively inhibit the proliferation of MCF-7 human breast cells while being nontoxic to human dermal fibroblasts (HDF). Collectively, the prepared nanocomposite drug delivery platform might be promising for the long-term and controlled release of capsaicin for the prevention and treatment of cancer.

Formulation Development and Evaluation of Indian Propolis Hydrogel for Wound Healing

Flavonoids and polyphenolic compounds play a key role in wound healing cycle modulation. Propolis, a natural bee product, has been widely reported as an enriched source of polyphenols and flavonoids as important chemical constituents and for its wound healing potential. The goal of this study was to develop and characterize a propolis-based polyvinyl alcohol (PVA) hydrogel composition with wound healing potential. To understand the impacts of critical material attributes and process parameters, formulation development was carried out using a design of experiment approach. A preliminary phytochemical analysis of Indian propolis extract showed the presence of flavonoids (23.61 ± 0.0452 mg equivalent of quercetin/g) and polyphenols (34.82 ± 0.0785 mg equivalent of gallic acid/g), both of which aid in wound healing and skin tissue regeneration. The pH, viscosity, and in vitro release of the hydrogel formulation were also studied. The burn wound healing model results revealed significant (p < 0.0001) wound contraction by propolis hydrogel (93.58 + 0.15%) with rapid re-epithelialization relative to 5% w/w povidone iodine ointment USP (Cipladine^®) (95.39 + 0.16%). The excision wound healing model confirms significant (p < 0.0001) wound contraction by propolis hydrogel (91.45 + 0.29%) with accelerated re-epithelialization comparable to 5% w/w povidone iodine ointment USP (Cipladine^®) (94.38 + 0.21%). The developed formulation offers promise for wound healing, which may be investigated further for clinical research.

Decellularized Extracellular Matrix for Remodeling Bioengineering Organoid's Microenvironment

Over the past decade, stem cell- and tumor-derived organoids are the most promising models in developmental biology and disease modeling, respectively. The matrix is one of three main elements in the construction of an organoid and the most important module of its extracellular microenvironment. However, the source of the currently available commercial matrix, Matrigel, limits the application of organoids in clinical medicine. It is worth investigating whether the original decellularized extracellular matrix (dECM) can be exploited as the matrix of organoids and improving organoid construction are very important. In this review, tissue decellularization protocols and the characteristics of decellularization methods, the mechanical support and biological cues of extraccellular matrix (ECM), methods for construction of multifunctional dECM and responsive dECM hydrogel, and the potential applications of functional dECM are summarized. In addition, some expectations are provided for dECM as the matrix of organoids in clinical applications.

Development of Adapalene Loaded Liposome Based Gel for Acne

Retinoids are considered the mainstay treatment for moderate to severe acne. Adapalene, a third-generation retinoid, has physiochemical properties which hinder the effective delivery of the drug to the skin. Therefore, the current study aimed to develop and evaluate adapalene liposomal loaded gel (ADA-LP gel) for the effective management of acne to improve tolerability and delivery to targeted sites as compared to the conventional dosage form of the drug. A novel spontaneous phase transition method (SPT) was used to formulate liposomes. Liposomal formulation (ADA-LP) was prepared and optimized based on particle size, zeta potential, and PDI. Optimized formulation was further characterized by different techniques and loaded into Carbopol gel. In vitro drug release, ex vivo permeation, and in vivo studies were performed using the prepared adapalene-loaded liposomal-based gel. The in vivo study was done employing the testosterone-induced acne model in mice. The optimized formulation had a size of 181 nm, PDI 0.145, and a zeta potential of -35 mV, indicating that the formulation was stable. Encapsulation efficiency was 89.69 ± 0.5%. ADA-LPs were loaded into the gel. Prepared ADA-LP showed a 79 ± 0.02% release of drug in a sustained manner, within 24 h. The ex vivo permeability study showed a total of 43 ± 0.06 µg/cm² of drug able to permeate through the skin within 24 h. Moreover, only 28.27 ± 0.04% was retained on the epidermis. The developed ADA-LP gel showed significant improvement in the acne lesions in mice with no visible scars and inflammation on the skin. Therefore, ADA-LP-based gel could be a promising carrier system for the safe and effective delivery of Adapalene.

Ultrasound-guided chemoradiotherapy of breast cancer using smart methotrexate-loaded perfluorohexane nanodroplets

Chemoradiotherapy with controlled-release nanocarriers such as sono-sensitive nanodroplets (NDs) can enhance the anticancer activity of chemotherapy medicines and reduces normal tissue side effects. In this study, folic acid-functionalized methotrexate-loaded perfluorohexane NDs with alginate shell (FA-MTX/PFH@alginate NDs) were synthesized, characterized, and their potential for ultrasound-guided chemoradiotherapy of breast cancer was investigated in vitro and in vivo. The cancer cell (4T1) viabilities and surviving fractions after NDs and ultrasound treatments were significantly decreased. However, this reduction was much more significant for ultrasound in combination with X-ray irradiation. The in vitro and in vivo results confirmed that MTX-loaded NDs are highly biocompatible and they have no significant hemolytic activity and organ toxicity. Furthermore, the in vivo results indicated that the FA-MTX/PFH@alginate NDs were accumulated selectively in the tumor region. In conclusion, FA-functionalized MTX/PFH@alginate NDs have a great theranostic performance for ultrasound-controlled drug delivery in combination with radiotherapy of breast cancer.

Biomedical Applications of Thermosensitive Hydrogels for Controlled/Modulated Piroxicam Delivery

The objectives of this study are the synthesis of thermosensitive poly(N-isopropylacrylamide-co-2-hydroxypropyl methacrylate), p(NiPAm-HPMet), hydrogels and the analysis of a drug-delivery system based on piroxicam, as a model drug, and synthesized hydrogels. A high pressure liquid chromatography method has been used in order to determine both qualitative and quantitative amounts of unreacted monomers and crosslinkers from polymerized hydrogels. Swelling kinetics and the order of a swelling process of the hydrogels have been analyzed at 10 and 40 °C. The copolymers' thermal properties have been monitored by the differential scanning calorimetry (DSC) method. DSC termograms have shown that melting occurs in two temperature intervals (142.36-150.72 °C and 153.14-156.49 °C). A matrix system with incorporated piroxicam has been analyzed by using FTIR and SEM methods. Structural analysis has demonstrated that intermolecular non-covalent interactions have been built between side-groups of copolymer and loaded piroxicam. Morphology of p(NiPAm-HPMet) after drug incorporation indicates the piroxicam presence into the copolymer pores. Kinetic parameters of the piroxicam release from hydrogels at 37 °C and pH 7.4 indicate that the fluid transport mechanism corresponds to Fickian diffusion. As a result, formulation of thermosensitive p(NiPAm-HPMet) hydrogels with incorporated piroxicam could be of interest for further testing as a drug carrier for modulated and prolonged release, especially for topical administration.

Electron Beam Irradiation Cross-Linked Hydrogel Patches Loaded with Red Onion Peel Extract for Transdermal Drug Delivery: Formulation, Characterization, Cytocompatibility, and Skin Permeation

The use of bioactive molecules derived from medicinal plants in wound healing has recently attracted considerable attention in both research and public interest. In this work, we demonstrated the first attempt to incorporate the extract from Thai red onion skins in hydrogel patches intended for transdermal delivery. The red onion skin extract (ROSE) was first prepared and evaluated for cytotoxicity by MTT assay with both L929 and human dermal fibroblast cells. Hydrogel patches with porous microstructure and high water content were fabricated from polyvinyl alcohol (PVA) by electron beam irradiation and characterized for their physical, mechanical, morphological, and cytocompatible properties prior to the loading of ROSE. After decontamination by electron beam irradiation, the in vitro release profile exhibited the burst release of extract from ROSE-coated hydrogel patches within 5 h, followed by the sustained release up to 48 h. Finally, evaluation of skin permeation using Franz cell setup with a newborn pig skin model showed that the permeation of ROSE from the hydrogel patch increased with time and reached the maximum of 262 µg/cm², which was well below the cytotoxicity threshold, at 24 h. These results demonstrated that our ROSE-coated hydrogel patches could potentially be used in transdermal delivery.

Flexible nano-liposomes-based transdermal hydrogel for targeted delivery of dexamethasone for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is an inflammatory immune-mediated disease that can lead to synovitis, cartilage destruction, and even joint damage. Dexamethasone (DEX) is a commonly used agent for RA therapy on inflammation manage. However, the traditional administering DEX is hampered by low efficiency and obvious adverse effects. Therefore, in order to efficiently deliver DEX to RA inflamed joints and overcome existing deficiencies, we developed transdermal formation dextran sulfate (DS) modified DEX-loaded flexible liposome hydrogel (DS-FLs/DEX hydrogel), validated their transdermal efficiency, evaluated its ability to target activated macrophages, and its anti-inflammatory effect. The DS-FLs/DEX exhibited excellent biocompatibility, sustainable drug release, and high uptake by lipopolysaccharide (LPS)-activated macrophages. Furthermore, the DS-FLs/DEX hydrogel showed desired skin permeation as compared with regular liposome hydrogel (DS-RLs/DEX hydrogel) due to its good deformability. In vivo, when used the AIA rats as RA model, the DS-FLs/DEX hydrogel can effectively penetrate and accumulate in inflamed joints, significantly improve joint swelling in RA rats, and reduce the destructive effect of RA on bone. Importantly, the expression of inflammatory cytokines in joints was inhibited and the system toxicity did not activate under DS-FLs/DEX hydrogel treatment. Overall, these data revealed that the dextran sulfate (DS) modified DEX-loaded flexible liposome hydrogel (DS-FLs/DEX hydrogel) can prove to be an excellent drug delivery vehicle against RA.

Transdermal delivery of allopurinol-loaded nanostructured lipid carrier in the treatment of gout

BACKGROUND

Allopurinol (ALP), a xanthine oxidase inhibitor, is a first line drug for the treatment of gout and hyperuricemia. Being the member of BCS class II drugs, ALP has solubility problem, which affects its bioavailability. Also, ALP has shorter half-life and showed GI related problems. In present study, ALP was encapsulated in nanostructured lipid carriers (NLCs) to ensure enhanced bioavailability, improved efficacy and safety in vivo.

METHODOLOGY

ALP-loaded NLCs were fabricated by micro-emulsion technique. The prepared NLCs were optimized via design expert in term of particle size, zeta potential and entrapment efficiency. FTIR, PXRD and TEM analysis were carried out to check chemical interaction, polymorphic form and surface morphology of the optimized formulation. ALP-loaded NLCs were then loaded into HPMC based poloxamer-407 gel and were characterized. In vitro and ex vivo analysis were carried out via dialysis membrane method and franz diffusion cell, respectively. Uric acid was used for induction of gout and the anti-gout activity of ALP-loaded NLCs gel was performed and compared with ALP suspension.

RESULTS

The optimized formulation had particles in nano-range (238.13 nm) with suitable zeta potential (-31.5 mV), poly-dispersity index (0.115) and entrapment of 87.24%. FTIR results confirmed absence of chemical interaction among formulation ingredients. XRD indicated amorphous nature of ALP-loaded NLCs, whereas TEM analysis confirmed spherical morphology of nanoparticles. The optimized formulation was successfully loaded in to gel and characterized accordingly. The in vitro release and drug release kinetics models showed sustained release of the drug from ALP-loaded NLCs gel. Furthermore, about 28 fold enhanced permeation was observed from ALP-loaded NLCs gel as compared to conventional gel. Skin irritation study disclosed safety of ALP-loaded NLCs gel for transdermal application. Furthermore, ALP-loaded NLCs gel showed significantly enhanced anti-gout activity in Sprague-Dawley rats after transdermal administration as compared to oral ALP suspension.

CONCLUSION

ALP-loaded NLCs gel after transdermal administration sustained the drug release, avoid gastrointestinal side effects and enhance the anti-gout performance of ALP. It can be concluded, that NLCs have the potential to deliver drugs via transdermal route as indicated in case of allopurinol.

In Vitro and Ex Vivo Evaluation of Fluocinolone Acetonide-Acitretin-Coloaded Nanostructured Lipid Carriers for Topical Treatment of Psoriasis

Psoriasis is chronic autoimmune disease that affects 2-5% of the global population. Fluocinolone acetonide (FLU) and acitretin (ACT) are widely used antipsoriatic drugs that belong to BCS classes II and IV, respectively. FLU exhibits side effects, such as skin irritation and a burning sensation. ACT also shows adverse effects, such as gingivitis, teratogenic effects and xerophthalmia. In the present study, topical nanostructured lipid carriers (NLCs) were fabricated to reduce the side effects and enhance the therapeutic efficacy. FLU-ACT-coloaded NLCs were prepared by the modified microemulsion method and optimized by the Box-Behnken model of Design Expert® version 12. The optimization was based on the particle size (PS), zeta potential (ZP) and percentage of encapsulation efficiency (%EE). The physicochemical analyses were performed by TEM, FTIR, XRD and DSC to assess the morphology, chemical interactions between excipients, crystallinity and thermal behavior of the optimized FLU-ACT-coloaded NLCs. The FLU-ACT-coloaded NLCs were successfully loaded into gel and characterized appropriately. The dialysis bag method and Franz diffusion cells were used for the in vitro release and ex vivo permeation studies, respectively. The optimized FLU-ACT-coloaded NLCs had the desired particle size of 288.2 ± 2.3 nm, ZP of -34.2 ± 1.0 mV and %EE values of 81.6 ± 1.1% for ACT and 75 ± 1.3% for FLU. The TEM results confirmed the spherical morphology, while the FTIR results showed the absence of chemical interactions of any type among the ingredients of the FLU-ACT-coloaded NLCs. The XRD and DSC analyses confirmed the amorphous nature and thermal behavior. The in vitro study showed the sustained release of the FLU and ACT from the optimized FLU-ACT-coloaded NLCs and FLU-ACT-coloaded NLC gel compared with the FLU-ACT suspension and conventional gel. The ex vivo study confirmed the minimal permeation of both drugs from the FLU-ACT-coloaded NLC gel.

Layer-by-Layer Vaginal Films for Acyclovir Controlled Release to Prevent Genital Herpes

Genital herpes is one of the most common sexually transmitted infections worldwide. It mainly affects women, as the rate of sexual transmission from male-to-female is higher than from female-to-male. The application of vaginal antivirals drugs could reduce the prevalence of genital herpes and prevent future infections. Layer-by-layer vaginal films were prepared by the solvent evaporation method using iota-carrageenan, hydroxypropyl methylcellulose and the polymethacrylates Eudragit® RS PO and Eudragit® S100, for the controlled release of acyclovir. The films were characterized by texture analysis and Raman spectroscopy. Swelling, mucoadhesion, and drug release studies were conducted in simulated vaginal fluid. The results show that Layer-by-Layer films exhibited adequate mechanical properties. The structuring of the layer-by-layer films allowed the controlled release of acyclovir and produced a prolonged mucoadhesion residence time of up to 192h. The films formed in layer 2 by the combination of Eudragit® RS PO and S100 showed a controlled release of acyclovir for eight days, and adequate mechanical properties. These promising formulations for the prevention of genital herpes deserve further evaluation.

Formulation Development and Characterization of pH Responsive Polymeric Nano-Pharmaceuticals for Targeted Delivery of Anti-Cancer Drug (Methotrexate)

Oral administration of pH sensitive/stimuli responsive nanoparticles are gaining importance because of the limited side effects, minimum dose and controlled drug release. The objective of this study was to develop and evaluate pH sensitive polymeric nanoparticles for methotrexate with the aim to maximize the drug release at target site. In the presented study, pH sensitive polymeric nanoparticles of methotrexate were developed through modified solvent evaporation technique using polymer Eudragit S100. Different process parameters like drug to polymer ratio, speed of sonication, concentration of surfactant and time of sonication were optimized by evaluating their effects on particle size, PDI, zeta potential, entrapment/encapsulation efficiency. The developed formulations were evaluated for their size, polydispersity (PDI), zeta potential, encapsulation efficiency, XRD, scanning electron microscopy, in-vitro drug release and stability studies. Best results were obtained with poloxamer-407 and PVA and were selected as surfactants. Physicochemical characterization of the developed formulations showed that the particle size lies in the range 165.7 ± 1.85–330.4 ± 4.19, PDI 0.119 ± 0.02–0.235 ± 0.008, zeta potential −0.163 ± 0.11–−5.64 ± 0.36 mV, and encapsulation efficiency more than 61%. The results of scanning electron microscopy revealed that nanoparticles have regular geometry with spherical shape. Initially the drug release occur through diffusion followed by erosion. The present studies showed that MTX-ES100 nanoparticles prepared during this study have the desired physicochemical properties, surface morphology and release characteristics used to target the desired organs.

A hyaluronic acid-based nanogel for the co-delivery of nitric oxide (NO) and a novel antimicrobial peptide (AMP) against bacterial biofilms

Biofilms are a global health concern because they are associated with chronic and recurrent infections as well as resistance to conventional antibiotics. The aim of this study was to prepare a nanogel for the co-delivery of NO and AMPs against bacteria and biofilms. The NO-releasing nanogel was prepared by crosslinking HA solution with divinyl sulfone and extensively characterized. The nanogel was found to be biocompatible, injectable and NO release from the gel was sustained over a period of 24 h. In vitro antibacterial studies showed that the NO-AMP-loaded nanogel exhibited a broad spectrum antibacterial/antibiofilm activity. The NO-releasing nanogel had a greater antibacterial effect when compared to NO alone with MIC values of 1.56, 0.78 and 0.39 μg/ml against Escherichia coli, Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa bacteria respectively. The antibiofilm results showed there was a 12.5 and 24-folds reduction in biofilms of MRSA, and P. aeruginosa respectively for catheters exposed to nanogel loaded with AMP/NO when compared to only NO, while a 7 and 9.4-folds reduction in biofilms of MRSA, and P. aeruginosa respectively was displayed by the nanogel loaded with only NO compared to only NO. The AMP/NO-releasing nanogel showed the potential to combat both biofilms and bacterial infections.

Hydrogel Containing Solid Lipid Nanoparticles Loaded with Argan Oil and Simvastatin: Preparation, In Vitro and Ex Vivo Assessment

Transdermal hydrogels have the potential to improve therapeutic outcomes via enhancing bioavailability and reducing toxicity associated with oral delivery. The goal of the present study was to formulate and optimise argan oil loaded transdermal hydrogel containing lipid nanoparticles. The high pressure homogenization (HPH) method was utilised to fabricate Simvastatin loaded solid lipid nanoparticles (SIM-SLNs) with precirol ATO 5 as a lipid core and Poloxamer 407 (P407) to stabilise the core. The optimised nanoformulation was characterised for its particle diameter, zeta potential, surface morphology, entrapment efficiency, crystallinity and molecular interaction. Furthermore, transdermal hydrogel was characterised for physical appearance, rheology, pH, bio adhesion, extrudability, spreadability and safety profile. In vitro and ex vivo assays were executed to gauge the potential of SLNs and argan oil for transdermal delivery. The mean particle size, zeta potential and polydispersity index (PDI) of the optimised nanoparticles were 205 nm, −16.6 mV and 0.127, respectively. Crystallinity studies and Fourier transform infrared (FTIR) analysis revealed no molecular interaction. The in vitro release model explains anomalous non-Fickian release of drug from matrix system. Ex vivo skin penetration studies conducted through a fluorescence microscope confirmed penetration of the formulation across the stratum corneum. Hydrogel plays a crucial role in controlling the burst release and imparting the effect of argan oil as hypolipidemic agent and permeation enhancer.

Azelaic acid loaded chitosan and HPMC based hydrogels for treatment of acne: formulation, characterization, in vitro-ex vivo evaluation

In this study, hydrogels containing azelaic acid were developed using chitosan or HPMC (1-7%) for local treatment of acne vulgaris. Physicochemical properties such as viscosity, pH and mechanical properties were evaluated. In vitro release and ex vivo permeability studies were performed using Franz diffusion cell system. The pH of the hydrogels were highly compatible with the skin pH and varied between 4.38-5.84. The cumulative release percentages of the hydrogels at the end of 6 hours were 65-78%, whereas the marketed product yielded 50% drug release. According to the ex vivo permeability results, azelaic acid accumulated in the skin were found to be 9.38 ± 0.65% (marketed cream), 19.53 ± 1.06% (K3), 10.96 ± 1.91% (H6). The antiacne studies with Cutibacterium acnes revealed that K3 (29.45 ± 0.95) and H6 (32.35 ± 0.15) had higher inhibition zones compared to the marketed cream (24.50 ± 0.90). Additionally, the gels were found to be highly stable as a result of the stability studies for 6 months. Among the hydrogels that were prepared based on experimental findings, K3 (3% Chitosan) and H6 (6% HPMC) represented elevated in vitro release profile, higher permeability and increased antiacne activity. The findings of this research suggest that the developed hydrogels might be an alternative to the marketed product.

Development and In Vitro/In Vivo Evaluation of pH-Sensitive Polymeric Nanoparticles Loaded Hydrogel for the Management of Psoriasis

Methotrexate (MTX), the gold standard against psoriasis, poses severe problems when administered systemically viz increased toxicity, poor solubility and adverse reactions. Hence, a topical formulation of MTX for the management of psoriasis can be an effective approach. The present study aimed to develop an MTX based nanoparticle-loaded chitosan hydrogel for evaluating its potential efficacy in an imiquimod-induced psoriatic mice model. MTX-NPs loaded hydrogel was prepared and optimized using the o/w emulsion solvent evaporation method. Particle size, zeta potential, entrapment efficiency, in vitro drug release, ex vivo permeation, skin irritation and deposition studies were performed. Psoriatic Area and Severity Index (PASI) score/histopathological examinations were conducted to check the antipsoriatic potential of MTX-NPs loaded hydrogel using an imiquimod (IMQ)-induced psoriatic model. Optimized MTX-NPs showed a particle size of 256.4 ± 2.17 nm and encapsulation efficiency of 86 ± 0.03%. MTX-NPs loaded hydrogel displayed a 73 ± 1.21% sustained drug release in 48 h. Ex vivo permeation study showed only 19.95 ± 1.04 µg/cm2 of drug permeated though skin in 24 h, while epidermis retained 81.33% of the drug. A significant decrease in PASI score with improvement to normalcy of mice skin was observed. The developed MTX-NPs hydrogel displayed negligible signs of mild hyperkeratosis and parakeratosis, while histopathological studies showed healing signs of mice skin. So, the MTX-NPs loaded hydrogel can be a promising delivery system against psoriasis.

Development of an intelligent, stimuli-responsive transdermal system for efficient delivery of Ibuprofen against rheumatoid arthritis

The present study aimed to fabricate and evaluate the therapeutic efficacy of pH-responsive Ibuprofen (IB) nanoparticles (NPs) loaded transdermal hydrogel against rheumatoid arthritis (RA). The IB loaded Eudragit® L 100 (EL 100) nanoparticles were formulated through a modified nanoprecipitation technique and optimized using central composite design software. The optimized NPs were loaded into Carbopol® 934-based hydrogel by solvent evaporation method and were analyzed for physicochemical characteristics. The mean particle size of the prepared NPs was 48 nm with an entrapment efficiency of 90%. The transdermal hydrogel showed a pH-responsive sustained drug release and high penetration through the skin. Moreover, the prepared nanocarrier system exhibited therapeutic efficacy at inflamed joints' sites both in acute and chronic RA mice model. The therapeutic efficacy of the prepared formulation was confirmed through the results of various behavioral, biochemical, and cytokines-based assays. Similarly, the assessment of histopathological and radiological images, as well as the skin irritation studies further strengthens the potential use of the prepared formulation through the transdermal route. The current findings suggested that IB loaded pH-responsive NPs based transdermal hydrogel can be used as an efficient agent to manage RA.

Osteo-conductive hydrogel scaffolds of poly(vinylalcohol) with silk fibroin particles for bone augmentation: Structural formation and in vitro testing

Bone augmentation is an effective approach to treat patients who have bone loss at the maxillofacial area. In this research, osteo-conductive hydrogel scaffolds of poly(vinylalcohol) (PVA) with silk fibroin particles (SFP) were fabricated. The SFP were formed by dropping a solution of silk fibroin into acetone at different volume ratios (v/v) of silk to acetone: 1:3 (SFP-3), 1:6 (SFP-6), 1:12 (SFP-12), and 1:24 (SFP-24). The various SFP solutions were mixed with a PVA solution before fabrication into hydrogels by freeze-thawing. Afterwards, the hydrogels were freeze-dried to fabricate the scaffolds. The particle size and charge, molecular organization, and morphology of the SFP were characterized and observed with dynamic light scattering, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy (SEM). The morphologies of the hydrogel scaffolds were observed with SEM. Swelling percentage was used to assess the swelling behavior of the hydrogel scaffolds. The mechanical properties were also tested. The scaffolds were cultured with osteoblast cells to test the biological performance, cell viability and performance, alkaline phosphatase activity, calcium deposition, and total protein. The SFP-24 was the smallest in particle size. PVA hydrogel scaffolds with SFP-24 demonstrated low particle aggregation, good particle distribution within the scaffold, and a lower swelling percentage. PVA hydrogel scaffolds with SFP had higher mechanical stability than scaffolds without the SFP. Furthermore, the PVA hydrogel scaffold with SFP-24 had better biological performance. Finally, the results demonstrated that PVA hydrogel scaffolds with SFP-24 showed good osteo-conductive performance which is promising for bone augmentation.

Development of novel biopolymer-based nanoparticles loaded cream for potential treatment of topical fungal infections

OBJECTIVE

Biodegradable polymers are extensively used due to their efficient safety profiles. The aim of the current study was to fabricate, evaluate, and characterize biodegradable, biocompatible fluconazole (FLZ) loaded chitosan (CHS) chondroitin sulfate (CS) nanoparticles (NPs) for topical delivery. Polymers utilized in the formulation not only served as a carrier system but also aided in fighting with complex etiology of the disease due to their innate antifungal activities.

METHODS

NPs were prepared by the complex coacervation method, then were optimized for various parameters and subsequently loaded into a cream.

RESULTS

Scanning electron microscopic (SEM) analysis showed spherical morphology of the NPs. Prepared NPs showed an average particle size in the range of 350-450 nm and an encapsulation efficiency (EE) of 86%. The polydispersity index (PDI) was found to be 0.148 that showed a uniform distribution of NPs. Fourier transform infrared (FTIR) spectroscopy confirmed the absence of any electrostatic interaction between ingredients. In vitro drug release analyses exhibited a sustained release of the drug and higher antifungal activity than free FLZ. Ex vivo permeability and drug distribution in different skin layers ensured a site-specific delivery of the FLZ-NPs. As compared with free FLZ and other control groups, the prepared NPs also exhibited significantly higher antifungal activity against Candida albicans (p < .01).

CONCLUSION

It was concluded from the results that the FLZ-NPs laden cream could be a potential candidate for topical and site-specific delivery of the drug cargo for the potential treatment of fungal infections.

Development and Characterization of n-Propyl Gallate Encapsulated Solid Lipid Nanoparticles-Loaded Hydrogel for Intranasal Delivery

The objective of the present study was to develop n-propyl gallate-loaded solid lipid nanoparticles (PG-SLNs) in a hydrogel (HG) formulation using Transcutol-P (TC-P) as a permeation enhancer. Modified solvent injection technique was applied to produce optimized PG-SLNs via the Quality by Design approach and central composite design. The in vitro mucoadhesion, scavenging activity, drug release, permeation studies of PG from PG-SLNs-loaded HG were evaluated under simulated nasal conditions. Compared with in vitro release behavior of PG from SLNs, the drug release from the PG-SLNs-loaded HG showed a lower burst effect and sustained release profile. The cumulative permeation of PG from PG-SLNs-loaded HG with TC-P was 600 μg/cm² within 60 min, which is 3–60-fold higher than PG-SLNs and native PG, respectively. Raman mapping showed that the distribution of PG-SLNs was more concentrated in HG having lower concentrations of hyaluronic acid. The scavenging assay demonstrated increased antioxidant activity at higher concentrations of HG. Due to enhanced stability and mucoadhesive properties, the developed HG-based SLNs can improve nasal absorption by increasing residence time on nasal mucosa. This study provides in vitro proof of the potential of combining the advantages of SLNs and HG for the intranasal delivery of antioxidants.

Delivering therapeutic cannabinoids via skin: Current state and future perspectives

Adequate evidence exists in the literature indicating a relatively positive shift with regards to the legal acceptance of cannabis and cannabis-derived products for medicinal purposes in some countries. Concomitantly, scientists are showing renewed interest in cannabis-related research work. Over the years, clinical and preclinical studies have demonstrated the therapeutic significance of cannabinoids for diverse indications. Additionally, efforts are being made to develop cannabis-related products into acceptable prescription products. FDA authorization for the commercial use of four cannabinoid-derived products, available as oral dosage forms is a significant progress already. However, there are certain drawbacks associated with the conventional delivery forms of cannabinoids. These include low oral bioavailability due to hepatic degradation, gastric instability, poor water solubility, and the side effects experienced upon the use of high doses of psychotropic cannabinoids associated with heightened plasma concentrations of the drug. These are however, limitable with the aid of transcutaneous drug delivery. Emerging topical and transdermal strategies could be exploited for the successful development of highly effective delivery systems for cannabinoids. This review discusses the feasibility of delivering therapeutic cannabinoids via skin and provides a comprehensive account of the supporting research studies that have been reported in the literature till date.

Topical delivery of curcumin-loaded transfersomes gel ameliorated rheumatoid arthritis by inhibiting NF-κβ pathway

Aim: To fabricate and evaluate curcumin-loaded transfersomes (Cur-TF) for the targeted delivery and enhanced therapeutic efficacy of curcumin for the treatment of rheumatoid arthritis (RA). Methods: Modified thin-film hydration method was used to prepare Cur-TF which were then embedded into carbopol-934 gel. They were further evaluated through in vitro techniques and in an in vivo arthritis model. Results: Cur-TF had optimal particle size, spherical morphology, high encapsulation efficiency and sustained drug release profiles. The Cur-TF gel had better in vitro skin penetration than plain curcumin. In vivo findings demonstrated improved clinical, histological and x-ray scores and reduced pro-inflammatory cytokines through NF-κβ inhibition. Conclusion: Cur-TF gel delivered curcumin to the arthritic dermal tissue through a topical route and demonstrated promising therapeutic efficacy by significantly alleviating complete Freud's adjuvant (CFA)-induced arthritis.

An efficient approach for development and optimisation of curcumin-loaded solid lipid nanoparticles' patch for transdermal delivery

This study aimed to develop and optimise a Curcumin-loaded SLNs (C-SLNs) patch through a new approach for transdermal delivery. C-SLNs were optimised through the response surface central composite design using the modified injection method. Optimised C-SLNs were loaded into a polyvinyl alcohol-based patch through the backing membrane method. Compatibility studies (FTIR, XRPD), in vitro release, ex vivo skin permeation, accelerated stability, and evaluation studies of the patch were also performed. Prepared C-SLNs exhibited average particle diameter of 170 ± 2 nm with an encapsulation efficiency of 90 ± 3.5% (w/w) while SEM illustrated spherical shape of particles. In vitro release data ensured a sustained release for up to 72 hours. The enhancement ratio of C-SLNs based patch with permeation enhancer (PE) was high up to 6.5 folds as compared to patch without PE. It is concluded that the modified injection method is simple, economical, and less time consuming for the development of C-SLNs patch for the transdermal route.

Emerging Role of Hydrogels in Drug Delivery Systems, Tissue Engineering and Wound Management

The popularity of hydrogels as biomaterials lies in their tunable physical properties, ability to encapsulate small molecules and macromolecular drugs, water holding capacity, flexibility, and controllable degradability. Functionalization strategies to overcome the deficiencies of conventional hydrogels and expand the role of advanced hydrogels such as DNA hydrogels are extensively discussed in this review. Different types of cross-linking techniques, materials utilized, procedures, advantages, and disadvantages covering hydrogels are tabulated. The application of hydrogels, particularly in buccal, oral, vaginal, and transdermal drug delivery systems, are described. The review also focuses on composite hydrogels with enhanced properties that are being developed to meet the diverse demand of wound dressing materials. The unique advantages of hydrogel nanoparticles in targeted and intracellular delivery of various therapeutic agents are explained. Furthermore, different types of hydrogel-based materials utilized for tissue engineering applications and fabrication of contact lens are discussed. The article also provides an overview of selected examples of commercial products launched particularly in the area of oral and ocular drug delivery systems and wound dressing materials. Hydrogels can be prepared with a wide variety of properties, achieving biostable, bioresorbable, and biodegradable polymer matrices, whose mechanical properties and degree of swelling are tailored with a specific application. These unique features give them a promising future in the fields of drug delivery systems and applied biomedicine.

Quality-by-Design-Based Development of n-Propyl-Gallate-Loaded Hyaluronic-Acid-Coated Liposomes for Intranasal Administration

The present study aimed to develop n-propyl gallate (PG)-encapsulated liposomes through a novel direct pouring method using the quality-by-design (QbD) approach. A further aim was to coat liposomes with hyaluronic acid (HA) to improve the stability of the formulation in nasal mucosa. The QbD method was used for the determination of critical quality attributes in the formulation of PG-loaded liposomes coated with HA. The optimized formulation was determined by applying the Box–Behnken design to investigate the effect of composition and process variables on particle size, polydispersity index (PDI), and zeta potential. Physiochemical characterization, in vitro release, and permeability tests, as well as accelerated stability studies, were performed with the optimized liposomal formulation. The optimized formulation resulted in 90 ± 3.6% encapsulation efficiency, 167.9 ± 3.5 nm average hydrodynamic diameter, 0.129 ± 0.002 PDI, and −33.9 ± 4.5 zeta potential. Coated liposomes showed significantly improved properties in 24 h in an in vitro release test (>60%), in vitro permeability measurement (420 μg/cm²) within 60 min, and also in accelerated stability studies compared to uncoated liposomes. A hydrogen-peroxide-scavenging assay showed improved stability of PG-containing liposomes. It can be concluded that the optimization of PG-encapsulated liposomes coated with HA has great potential for targeting several brain diseases.

The role of internal and external stimuli in the rational design of skin-specific drug delivery systems

The concept of skin-specific drug delivery with a spatio-temporal control has just recently received concerns in dermatology. Inspired by the progress in smart materials and their perspective application in medicine science, development of stimuli responsive drug delivery systems with skin-specificity has become possible, which has led to a new era in the localized treatment of skin diseases. This review highlights both the internal and external stimuli that have been employed in this field, with a focus on their implication on the rational design of pharmaceutical formulations, especially those nanoscale drug carriers that are able to provide release of payloads with a precise spatio-temporal control in response to specific stimuli. Also, the strategy of dual stimuli responsive drug delivery systems will be discussed for further improvement of the efficacy of skin drug delivery. The prominent examples of the established approaches are described as comprehensive and current as possible. The review is expected to provide some inspiration for utilizing different stimuli for realizing the site-specific and on-demand drug delivery to the skin.

Progress on Preparation of pH/Temperature-Sensitive Intelligent Hydrogels and Applications in Target Transport and Controlled Release of Drugs

Hydrogels with three-dimensional network structure, hydrophilic, and insoluble in water which are ideal carrier materials for intelligent drug delivery systems. Intelligent hydrogel has become a research frontier and hotspot because of its intelligence, high efficiency, safety, and convenience in drug controlled and prolonged release. It has a broad application prospect in the medicine and biomedicine fields and can lead the medicine fields into a new era of “precise treatment.” Based on the latest research progress, the main preparation methods of hydrogel and the development of the drug delivery system are briefly introduced. The most promising three intelligent hydrogels in the human physiological environment, namely, pH responsiveness, temperature responsiveness, and pH/temperature dual responsiveness, are emphatically reviewed. Their release mechanisms, targeting transport, and controlled-prolonged release of drug are also discussed. In addition, some suggestions for the main problems and future development were given.

Chitosan hydrogel for topical delivery of ebastine loaded solid lipid nanoparticles for alleviation of allergic contact dermatitis

Ebastine, is an antihistamine drug that exerts its effect upon oral administration in humans for the treatment of allergic contact dermatitis (ACD), it also has some systemic side effects like gastric distress, headache, drowsiness, and epistaxis. Moreover, topical corticosteroids are used for treatment of ACD, which causes the human skin to lose its thickness and elasticity. Hence, ebastine-loaded solid lipid nanoparticles (E-SLNs) were prepared and their topical efficacy against allergic contact dermatitis was determined. Compritol 888 ATO and tween 80 were used to prepare E-SLNs by cold dilution of the hot micro-emulsion. E-SLNs were optimized statistically by employing a central composite design using Design-Expert® version 11.0. Optimized E-SLNs showed spherical surface morphology, zeta potential of −15.6 ± 2.4 mV, PDI of 0.256 ± 0.03, and particle sizes of 155.2 ± 1.5 nm and th eentrapment efficiency of ebastine was more than 78%. Nanoparticles were characterized using FT-IR, XRD, and TEM. An E-SLNs loaded hydrogel was prepared using chitosan as a gelling agent and glutaraldehyde as a crosslinker. In vitro drug release studies performed for 24 hours on the E-SLNs dispersion and E-SLNs loaded hydrogel showed a sustained release of maximum 82.9% and 73.7% respectively. In vivo studies were conducted on BALB/c mice to evaluate the topical efficacy of the E-SLNs loaded hydrogel for allergic contact dermatitis. ACD was induced on the ear using picryl chloride solution. After induction, ears were treated daily with the E-SLNs loaded hydrogel for 15 days. Swelling behavior, mast cell count, and histopathological studies of the ear confirmed that the hydrogel alleviated the symptoms of allergic contact dermatitis.

Ebastine exerts its effect upon oral administration in humans for the treatment of allergic contact dermatitis (ACD), but it has some systemic side effects. Hence, ebastine-SLNs loaded hydrogel was prepared to increase topical efficacy of ebastine.

Recent trends, challenges and future outlook of transdermal drug delivery systems for rheumatoid arthritis therapy

At present, several drug molecules have been used for the treatment of rheumatoid arthritis (RA). However, the utilization of these compounds through the oral and parenteral route is limited due to low bioavailability, rapid metabolism, poor absorption, first-pass effect, and serious adverse effects. A transdermal delivery system is an appealing option in this scenario, as it possesses the proficiency to overcome drawbacks associated with the oral and parenteral route. With the innovation of several enhancement strategies, many therapeutic agents have been administered transdermally, proposing an exceptional approach to treat RA. The present article provides an insight into the etiology and pathophysiology of RA. The challenges of the transdermal route and the strategies to improve those problems are described. The current advances in increasing the transdermal efficiency of the therapeutics against RA are discussed. Limitations and advantages regarding the state of the art transdermal delivery system and future outlook are also summarized.

Triggering doxorubicin release from responsive hydrogel films by polyamine uptake

Polyamines such as putrescine, spermidine and spermine are required in many inter- and intra-cellular processes. There is, however, evidence of anomalously high concentrations of these polyamines around cancer cells. Furthermore, high polyamine concentrations play a key role in accelerating the speed of cancer proliferation. Some current therapies target the reduction of the polyamine concentration to delay the cancer advance. In this study, we use a molecular theory to prove the concept that poly(methacrylic acid) (PMAA) hydrogels can play the dual role of incorporating and retaining polyamines as well as releasing preloaded drugs in response. Towards such a goal, we have developed a molecular model for each of the chemical species, which includes the shape, size, charge, protonation state, and configuration. Our results indicate that PMAA hydrogel films can incorporate significant amounts of polyamines; this absorption increases with the solution concentration of the polyamines. Doxorubicin was chosen as a model drug for this study, which can be successfully incorporated within the film; the optimal encapsulation conditions occur at low salt concentrations and pH values near neutral. Polyamine absorption within the film results in the desorption of the drug from the hydrogel. An increase in the concentration of the polyamines enhances the drug release. To validate our theoretical findings, poly(methacrylic acid) hydrogel thin films were synthesized by atom transfer radical polymerization. Absorption/desorption experiments followed by UV-Vis spectroscopy demonstrate doxorubicin encapsulation within these films and polyamine-dependent drug release.

Exploiting proteases for cancer theranostic through molecular imaging and drug delivery

The measurement of biological processes at a molecular and cellular level serves as a basis for molecular imaging. As compared with traditional imaging approaches, molecular imaging functions to probe molecular anomalies that are the basis of a disease rather than the evaluation of end results of these molecular changes. Proteases play central role in tumor invasion, angiogenesis and metastasis thus can be exploited as a target for imaging probes in early diagnosis and treatment of tumors. Molecular imaging of protease has undergone tremendous breakthroughs in the field of diagnosis. It allows the clinicians not only to see the tumor location but also provides an insight into the expression and activity of different types of markers associated with the tumor microenvironment. These imaging techniques are expected to have a huge impact on early cancer detection and personalized cancer treatment. Effective development of protease imaging probes with the highest in vivo biocompatibility, stability and most appropriate pharmacokinetics for clinical translation will upsurge the success level of early cancer detection and treatment.

Polymeric nanoparticles based on carboxymethyl chitosan in combination with painless microneedle therapy systems for enhancing transdermal insulin delivery

Biodegradable nanoparticles (NPs) have been frequently used as insulin transdermal delivery vehicles due to their grand bioavailability, better encapsulation, controlled release and less toxic properties. However, the skin's barrier properties prevent insulin-loaded NP permeation at useful levels. Nowadays, microneedles have been spotlighted as novel transdermal delivery systems due to their advantages such as painlessness, efficient penetration and no hazardous residues. Herein, we introduce polymeric nanocarriers based on carboxymethyl chitosan (CMCS) for insulin delivery, combining with microneedle therapy systems, which can rapidly deliver insulin (INS) into the skin. The resulting CMCS-based nanocarriers are spherical nanoparticles with a mean size around 200 nm, which could generate supramolecular micelles to effectively encapsulate insulin (EE% = 83.78 ± 3.73%). A nanocrystalline microneedle array (6 × 6, 75/150 μm) was used to penetrate the stratum corneum (SC) for enhancing transdermal insulin delivery, while minimizing the pain sensation caused by intravenous injection. Compared with the transdermal rate of passive diffusion [2.77 ± 0.64 μg (cm-2 h-1)], the transdermal rate of the insulin-loaded NP combined with microneedle penetration shows a 4.2-fold increase [10.24 ± 1.06 μg (cm-2 h-1)] from permeation experiment in vitro. In vivo hypoglycemic experiments demonstrate the potential of using nanocarrier combination with microneedle arrays for painless insulin delivery through the skin in a clinical setting. Thus, the developed combination scheme of nanoparticles and microneedle arrays offers an effective, user-friendly, and low-toxicity option for diabetes patients requiring long-term and multiple treatments.