Polysaccharide hydrogel platforms as suitable carriers of liposomes and extracellular vesicles for dermal applications

Berberine hydrochloride-loaded liposomes-in-hydrogel microneedles achieve the efficient treatment for psoriasis

Psoriasis is a common immune-mediated squamous skin disease, primarily characterized by the over proliferation of keratinocytes and a significant thickening of the stratum corneum. Traditional systemic drug delivery therapies often fall short due to low drug bioavailability and significant toxic side effects. Topical medications, while capable of achieving local or systemic treatment via transdermal routes, face limitations in psoriasis patients due to the abnormal thickening of the epidermis, which reduces skin permeability and hampers drug penetration efficiency. Hydrogel microneedles, as an emerging transdermal drug delivery technology, offer significant advantages such as high permeability, ease of use, low toxicity and side effects, and controlled release. Therefore, this study developed a liposome-hydrogel microneedle delivery system for the administration of berberine hydrochloride. We successfully prepared berberine hydrochloride-loaded liposomes (Ber-LPs) with high encapsulation efficiency and good stability, and integrated them into hydrogel microneedles crosslinked with PVA and PEGDA (Ber-LPs-PEGDA&PVA MNs) through a photocuring method. These microneedles exhibit an intact structure, high mechanical strength, and effective skin penetration. In vivo studies on anti-psoriatic effects showed that, compared to the model group, Ber-LPs-PEGDA&PVA MNs significantly alleviated imiquimod-induced psoriasis-like symptoms in mice, reduced skin epidermal thickness, decreased the expression levels of inflammatory cytokines, and lowered the expression of CD31 and VEGF, demonstrating excellent therapeutic efficacy. Additionally, the microneedles exhibited good drug release properties, antioxidant capacity, and biocompatibility. The novel hydrogel microneedle drug delivery system developed in this study offers a safe and effective solution for the treatment of psoriasis, with significant potential for clinical application.

Advanced therapeutic strategies using Thermo-sensitive chitosan/pectin hydrogel in the treatment of multiple cancers

Current cancer therapies including immunotherapy and chemotherapy produce adverse side effects that demand improved drug distribution methods. Research shows that thermosensitive chitosan/pectin-based hydrogels serve as an effective platform technology for drug delivery during cancer therapy because of their ability to control drug release at specific locations. The hydrogels perform temperature-triggered sol-gel phase shifts which enables prolonged drug delivery together with minimal toxic side effects. The biocompatible and biodegradable properties of these materials enable solutions against drug resistance and tumour heterogeneity challenges. Studies have demonstrated that these hydrogels enhance drug bioavailability, extend circulation time, and improve tumour targeting, leading to increased therapeutic efficacy and reduced systemic toxicity. Their ability to sustain drug release and penetrate tumour microenvironments makes them a promising strategy for overcoming drug resistance and tumour heterogeneity. Their ability to reproduce native tissue properties poses challenges that scientists must address through improved structural optimization approaches. The combination of latest nanotechnology innovations and interdisciplinary studies has sped up the creation of chitosan/pectin hydrogels for cancer treatment applications. This review highlights the significant advancements and demonstrated effectiveness of thermosensitive chitosan/pectin hydrogels in cancer treatment by exploring their design parameters alongside their drug release behaviour while discussing their potential medical applications.

An overview of recent advancements in 4D printing of alginate hydrogels for tissue regeneration

4D printing of alginate hydrogels has emerged as a transformative strategy in tissue engineering, enabling the fabrication of stimuli-responsive scaffolds that recapitulate the temporal and spatial complexities of native tissues. Leveraging alginate's tunable crosslinking, biocompatibility, and easy modification, recent research has demonstrated the successful design of constructs capable of programmable shape morphing in response to physiological stimuli. This review highlights recent advances in polymer design, including methacrylated, oxidized, and ligand-functionalized alginate derivatives, and cutting-edge 4D printing technologies such as extrusion-based and photopolymerization-based printing technologies. Notably, these systems have shown promising outcomes in regenerating cartilage, bone, vascular, and neural tissues. However, key challenges remain, including the standardization of shape-morphing quantification, enhancement of mechanical robustness, improvement of host tissue integration, and the replication of native tissue complexity. This review concludes with a critical evaluation of current limitations and future directions, highlighting the potential of integrating 4D alginate hydrogel systems with emerging technologies such as artificial intelligence, machine learning, organoid models, and bioelectronic interfaces to accelerate innovation and broaden their application in tissue engineering. By synthesizing recent advancements and offering insights into the implementation of 4D alginate hydrogels, this review aims to stimulate continued progress in this rapidly evolving field.

Chitosan-based hydrogels: A comprehensive review of transdermal drug delivery

This article provides a comprehensive review of chitosan-based hydrogels for transdermal drug delivery. It covers various aspects including the chemical structure of chitosan and its derivatives, crosslinking agents, hydrogel morphology, and drug loading and release behaviors. The review draws on 16 studies sourced from Scopus, focusing on how the composition and structure of hydrogels influence drug release. The chemical structure of chitosan and its derivatives, such as chitosan hydrochloride and quaternary ammonium chitosan, plays a crucial role in determining the mechanical properties and stability of hydrogels. Crosslinking agents, both chemical and physical, affect the hydrogel's strength and transparency as well as its drug release profile. Hydrogel morphology, including its porosity, significantly impacts drug loading capacity and release behavior. Hydrogel-based microneedles show potential in overcoming the limitations of traditional drug administration methods by enhancing skin penetration and drug loading efficiency. Additionally, factors such as swelling ratio, drug loading efficiency, and release behavior are influenced by crosslinking methods, material composition, and environmental conditions. This article concludes that the design and modification of chitosan-based hydrogels can optimize transdermal drug delivery by improving drug release profiles and stability.

Advanced disease therapeutics using engineered living drug delivery systems

Biological barriers significantly impede the delivery of nanotherapeutics to diseased tissues, diminishing therapeutic efficacy across pathologies such as cancer and inflammatory disorders. Although conventional strategies integrate multifunctional designs and molecular components into nanomaterials (NMs), many approaches remain insufficient to overcome these barriers. Key challenges, including inadequate drug accumulation at target sites and nonspecific biodistribution, persist in nanotherapeutic development. NMs, which harness the ability to precisely modulate drug delivery spatiotemporally and control release kinetics, represent a transformative platform for targeted cancer therapy. In this review, we highlight the biological obstacles limiting effective cancer treatment and evaluate how stimuli-responsive NMs address these constraints. By leveraging exogenous and endogenous stimuli, such NMs improve therapeutic specificity, reduce off-target effects, and amplify drug activity within pathological microenvironments. We systematically analyze the rational design and synthesis of stimuli-responsive NMs, driven by advances in oncology, biomaterials science, and nanoscale engineering. Furthermore, we highlight advances across NM classes-including polymeric, lipid-based, inorganic, and hybrid systems and explore functionalization approaches using targeting ligands, antibodies, and biomimetic coatings. Diverse delivery strategies are evaluated, such as small-molecule prodrug activation, peptide- and protein-based targeting, nucleic acid payloads, and engineered cell-mediated transport. Despite the promise of stimuli-responsive NMs, challenges such as biocompatibility, scalable fabrication, and clinical translation barriers must be addressed. By elucidating structure-function relationships and refining stimulus-triggered mechanisms, these NMs pave the way for transformative precision oncology strategies, enabling patient-specific therapies with enhanced efficacy and safety. This synthesis of interdisciplinary insights aims to catalyze innovation in next-generation nanomedicine for cancer treatment.

Advantages and therapeutic applications of different semisolids as vehicles for nano-based systems

The aim of this review is to highlight the role of semisolid systems as vehicles for nanovesicles and nanoparticles. In general, nanotechnology plays a critical role in facilitating the delivery of therapeutic agents to their active sites, and several nanocarrier systems have been explored for the topical administration of active components. The major disadvantage of the prepared nanosystems is their low viscosity, which reduces the time needed for enough absorption and negatively affects their stability and bioavailability. The role of semisolid systems is to overcome this limitation. In conclusion, this review presents an updated summary of recent advances in the use of semisolids as vehicles for various nanosystems through comprehensive scrutiny of the types of semisolids and their advantages and their role in enhancing the absorption of nanoparticles and nanovesicles.

Self-Healing Hydrogels with Intrinsic Antioxidant and Antibacterial Properties Based on Oxidized Hydroxybutanoyl Glycan and Quaternized Carboxymethyl Chitosan for pH-Responsive Drug Delivery

In this study, self-healing hydrogels were created using oxidized hydroxybutanoyl glycan (OHbG) and quaternized carboxymethyl chitosan (QCMCS), displaying antioxidant and antibacterial properties for pH-responsive drug delivery. The structures of the modified polysaccharides were confirmed through 1H NMR analysis. Double crosslinking in the hydrogel occurred via imine bonds (between the aldehyde group of OHbG and the amine group of QCMCS) and ionic interactions (between the carboxyl group of OHbG and the quaternized group of QCMCS). The hydrogel exhibited self-healing properties and improved thermal stability with an increase in OHbG concentration. The OHbG/QCMCS hydrogel demonstrated high compressive strength, significant swelling, and large pore size. Drug release profiles varied between pH 2.0 (96.57%) and pH 7.4 (63.22%). Additionally, the hydrogel displayed antioxidant and antibacterial effects without compromising the polysaccharides' inherent characteristics. No cytotoxicity was observed in any hydrogel samples. These findings indicate that the OHbG/QCMCS hydrogel is a biocompatible and stimuli-responsive drug carrier, with potential for various pharmaceutical, biomedical, and biotechnological applications.

Challenges and considerations in liposomal hydrogels for the treatment of infection

INTRODUCTION

Liposomal hydrogels are novel drug delivery systems that comprise preformed liposomes incorporated in hydrogels destined for mostly localized drug therapy, herewith antimicrobial therapy. The formulation benefits from versatility of liposomes as lipid-based nanocarriers that enable delivery of various antimicrobials of different lipophilicities, and secondary vehicle, hydrogel, that assures better retention time of formulation at the infection site. Especially in an era of alarming antimicrobial resistance, efficient localized antimicrobial therapy that avoids systemic exposure of antimicrobial and related side effects is crucial.

AREAS COVERED

We provide an overview of liposomal hydrogels that were developed for superior delivery of antimicrobials at different infections sites, with focus on skin and vaginal infections. The review summarizes the challenges of infection site and most common infection-causing pathogens and offers commentary on most relevant features the formulation needs to optimize to increase the therapy outcome. We discuss the impact of liposomal composition, size, and choice of polymer-forming hydrogel on antimicrobial outcome based on the literature overview and own experience in the field.

EXPERT OPINION

Liposomal hydrogels offer improved therapy outcome in localized antimicrobial therapy. By fine-tuning of liposomal as well as hydrogel properties, formulations with superior performance can be optimized targeting specific infection site.

Targeted nanoparticle delivery unleashes synergistic photothermal and immunotherapeutic effects against hepatocellular carcinoma

The substantial mortality and morbidity of hepatocellular carcinoma, representing 90% of liver cancers, poses a significant health burden. The effectiveness of traditional hepatocellular carcinoma treatments such as surgical resection, radiotherapy, and chemotherapy is limited, underscoring the need for innovative therapeutic strategies. To this end, we synthesized phthalyl-pullulan nanoparticles encapsulating IR780 (an NIR-responsive heptamethine cyanine dye) and R848 (resiquimod; a TLR7/8 agonist) (PIR NPs). Characterization confirmed the size and loading capacity of PIR NPs, and controlled release of R848 therefrom upon NIR irradiation, thereby establishing the potential of this versatile therapeutic tool. PIR NPs were readily taken up by Hepa 1-6 cells in vitro by targeting asialoglycoprotein receptors present on its cellular surface. In in vivo experiments combining photothermal therapy and immunotherapy, following the local near-infrared irradiation, the PIR NPs accumulated in tumor sites induced immunogenic cell death and activated a tumor-specific T-cell immune response, thus highlighting their potent antitumor efficacy. The combined efficacy of photothermal therapy and immunotherapy presents a promising avenue for addressing the shortcomings of traditional hepatocellular carcinoma interventions. This study contributes valuable insights into the development of more effective and targeted therapeutic approaches for hepatocellular carcinoma treatment.

Novel Liposome-Gel Formulations Containing a Next Generation Postbiotic: Characterization, Rheological, Stability, Release Kinetic, and In Vitro Antimicrobial Activity Studies

In recent years, in addition to the positive effects of probiotics and prebiotics on health, increasing research has shown that postbiotics also have significant potential in the health field. Postbiotics are bioactive components produced by probiotic bacteria during fermentation and may exhibit antimicrobial activity. This study investigated the antimicrobial effects of liposomal postbiotics formulated in gel. Various postbiotic-containing liposomal systems have been developed and optimized to prepare formulations. Optimized liposomes and liposomal postbiotic-containing gel forms were examined in terms of particle size, polydispersity index, zeta potential, structural properties, encapsulation efficiency, permeability, release profiles, and stability. Finally, the antimicrobial activities of the postbiotics and the optimum gel formulation LG1 were evaluated on Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus hirae, and Candida albicans strains using disk diffusion and microdilution methods. The optimum liposome formulation L1 was determined to have a particle size of 185.32 ± 0.80 nm, a polydispersity index of 0.206 ± 0.012, a zeta potential of 35.0 ± 0.5 mV, and an encapsulation efficiency of 17.52%. Its permeability was determined as 51.52% at the end of 6 h. In vitro release studies showed that the drug release profile was in accordance with first-order kinetics and suitable for controlled release. The findings show that formulated postbiotics have similar antimicrobial activity to free postbiotics. These results suggest that liposomal gel formulations support the antimicrobial effects of postbiotics while providing advantages of use. In conclusion, the findings contribute to a better understanding of the antimicrobial potential of postbiotics and lipogelosomal postbiotics and optimize their use in pharmaceutical applications.

Functional Nanostructured Lipid Carrier-Enriched Hydrogels Tailored to Repair Damaged Epidermal Barrier

In this study, a functional nanostructured lipid carriers (NLCs)-based hydrogel was developed to repair the damaged epidermal skin barrier. NLCs were prepared via a high-energy approach, using argan oil and beeswax as liquid and solid lipids, respectively, and were loaded with ceramides and cholesterol at a physiologically relevant ratio, acting as structural and functional compounds. Employing a series of surfactants and optimizing the preparation conditions, NLCs of 215.5 ± 0.9 nm in size and a negative zeta potential of -42.7 ± 0.9 were obtained, showing acceptable physical and microbial stability. Solid state characterization by differential scanning calorimetry and X-ray powder diffraction revealed the formation of imperfect crystal NLC-type. The optimized NLC dispersion was loaded into the gel based on sodium hyaluronate and xanthan gum. The gels obtained presented a shear thinning and thixotropic behavior, which is suitable for dermal application. Incorporating NLCs enhanced the rheological, viscoelastic, and textural properties of the gel formed while retaining the suitable spreadability required for comfortable application and patient compliance. The NLC-loaded gel presented a noticeable occlusion effect in vitro. It provided 2.8-fold higher skin hydration levels on the ex vivo porcine ear model than the NLC-free gel, showing a potential to repair the damaged epidermal barrier and nourish the skin actively.

Mitigating Critical Peripheral Nerve Deficit Therapy with Reactive Oxygen Species/Ca2+-Responsive Dynamic Hydrogel-Mediated mRNA Delivery

Critical peripheral nerve deficiencies present as one of the most formidable conundrums in the realm of clinical medicine, frequently culminating in structural degradation and derangement of the neuromuscular apparatus. Engineered extracellular vesicles (EVs) exhibit the potential to ameliorate nerve impairments. However, the advent of Wallerian degeneration (WD), an inexorable phenomenon that ensues post peripheral nerve injury, serves as an insurmountable impediment to the direct therapeutic efficacy of EVs. In this investigation, we have fashioned a dynamic network for the conveyance of PTEN-induced kinase 1 (PINK1) mRNA (E-EV-P@HPCEP) using an adaptive hydrogel with reactive oxygen species (ROS)/Ca2+ responsive ability as the vehicle, bearing dual-targeted, engineered EVs. This intricate system is to precisely deliver PINK1 to senescent Schwann cells (SCs) while concurrently orchestrating a transformation in the inflammatory-senescent milieu following injury, thereby stymying the progression of WD in peripheral nerve fibers through the stimulation of autophagy within the mitochondria of the injured cells and the maintenance of mitochondrial mass equilibrium. WD, conventionally regarded as an inexorable process, E-EV-P@HPCEP achieved functionalized EV targeting, orchestrating a dual-response dynamic release mechanism via boronate ester bonds and calcium chelation, effectuating an enhancement in the inflammatory-senescent microenvironment, which expedites the therapeutic management of nerve deficiencies and augments the overall reparative outcome.

Extracellular Vesicles in the Repair of Bone and Cartilage Injury: From Macro‐Delivery to Micro‐Modification

Extracellular vesicles (EVs) are intermediaries in intercellular signal transmission and material exchange and have attracted significant attention from researchers in bone and cartilage repair. These nanoscale vesicles hold immense potential in facilitating bone and cartilage repair and regeneration by regulating the microenvironment at an injury site. However, their in vivo utilization is limited by their self‐clearance and random distribution. Therefore, various delivery platforms have been developed to improve EV targeting and retention rates in target organs while achieving a controlled release of EVs. Additionally, engineering modification of EVs has been proposed to effectively enhance EVs' intrinsic targeting and drug‐loading abilities and further improve their therapeutic effects on bone and cartilage injuries. This review aims to introduce the biogenesis of EVs and their regulatory mechanisms in the microenvironment of bone and cartilage injuries and comprehensively discuss the application of EV‐delivery platforms of different materials and various EV engineering modification methods in treating bone and cartilage injuries. The review's findings can help advance EV research and develop new strategies for improving the therapy of bone and cartilage injuries.

Preparation of Phosphorylated Auricularia cornea var. Li. Polysaccharide Liposome Gel and Analysis of Its In Vitro Antioxidant Activity

In this study, Auricularia cornea var. Li. polysaccharides (ACP) were used as the research object to prepare liposome gel and determine its antioxidant activity in vitro. Phosphorylated Auricularia cornea var. Li. polysaccharides (P-ACP) were prepared via the phosphorylation of ACP by the phosphate method. Additionally, phosphorylated Auricularia cornea var. Li. polysaccharide liposomes (P-ACPL) were prepared using a reverse evaporation method. Finally, phosphorylated Auricularia cornea var. Li. polysaccharide liposome gel (P-ACPLG) was prepared by dispersing the P-ACPL in the gel matrix. The results show that the phosphorylation of the P-ACP was 15.51%, the containment rate of the P-ACPL was 84.50%, the average particle size was (192.2 ± 3.3) nm, and the particle size distribution map had a homogeneous peak, resulting in the particle dispersion being uniform and the polydispersion index (PDI) being 0.134 ± 0.021. The average Zeta potential was (-33.4 ± 0.57) mV. In addition, the in vitro antioxidant activity of the P-ACPL was slightly higher than that of the ACP and P-ACP. After the P-ACPL was emulsified into P-ACPLG, the DPPH, hydroxyl radical clearance, and reducing the ability of P-ACPL remained unchanged. In general, the P-ACPLG prepared in this study has good antioxidant activity in vitro and can retain the antioxidant activity of P-ACPL in vitro well.

Antiproliferative Imidazo-Pyrazole-Based Hydrogel: A Promising Approach for the Development of New Treatments for PLX-Resistant Melanoma

Aiming at developing a dermal formulation against melanoma, the synthesized imidazo-pyrazoles 2-phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole-7-carboxylic acid (3-methoxy-4-phenoxy-benzylidene)-hydrazide (4G) and 2-phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole-7-carboxylic acid (4-benzyloxy-3-methoxy-benzylidene)-hydrazide (4I) were screened on patient-isolated melanoma cells (MEOV NT) and on Vemurafenib (PLX4032)-resistant (MEOV PLX-R) ones. Since 4I on MEOV PLX-R cells was 1.4-fold more effective than PLX, a hydrogel formulation containing 4I (R4HG-4I) was prepared in parallel with an empty R4-based hydrogel (R4HG) using a synthesized antibacterial resin (R4) as gelling agent. Thanks to its high hydrophilicity, porosity (85%), and excellent swelling capability (552%), R4 allowed to achieve R4HG and R4HG-4I with high equilibrium degree of swelling (EDS) and equilibrium water content (EWC). Chemometric-assisted ATR-FTIR analyses confirmed the chemical structure of swollen and fully dried (R4HG-D and R4HG-4I-D) hydrogels. The morphology of R4HG-D and R4HG-4I-D was examined by optical microscopy and SEM, while UV-vis analyses were carried out to obtain the drug loading (DL%) and the encapsulation efficiency (EE%) of R4HG-4I. Potentiometric titrations were performed to determine the equivalents of NH3+ in both R4HG and R4HG-4I. The swelling and water release profiles of both materials and related kinetics were assessed by equilibrium swelling rate and water loss studies, respectively, while their biodegradability over time was assessed by in vitro degradation experiments determining their mass loss. Rheological experiments established that both R4HG and R4HG-4I are shear-thinning Bingham pseudoplastic fluids with low yield stress, thus assuring easy spreadability in a future topical application. Release studies evidenced a sustained and quantitative release of 4I governed mainly by diffusion. Upon favorable results from further experiments in a more realistic 3D model of melanoma, R4HG-4I could represent a starting point to develop new topical therapeutic options to adjuvate the treatments of melanoma cells also when resistant to currently available drugs.