Drug Release Research Articles

Production of Polyvinyl Alcohol/Amoxicillin – Chitosan/Collagen Hybrid Bilayer Membranes for Regeneration of Gingival Tissues

AbstractPeriodontal diseases, if untreated, can cause gum recession and tooth root exposure, resulting in infection and irreversible damage. Traditional treatments using autologous grafts are painful and often result in postoperative complications. Scaffolds offer a less invasive alternative, promoting cell proliferation and healing without additional surgery, thus enhancing comfort for patients and doctors. This study developed Chitosan (Chit)/Collagen (Col) film surfaces and drug‐loaded Polyvinyl Alcohol (PVA)/Amoxicillin (AMX) nanofibers using solvent casting and electrospinning methods, respectively. The surfaces are characterized by scanning electron microscopy (SEM), mechanical testing, Fourier Transform Infrared Spectroscopy (FTIR), and differential scanning calorimetry (DSC). Biocompatibility and antimicrobial properties are assessed using NIH/3T3 fibroblast cells and bacterial cultures. SEM images confirmed the structural integrity of AMX‐loaded 13% PVA nanofibers, while FTIR analysis validated the compositional integrity of PVA/AMX nanofibers and Chit/Col film hybrid surfaces. Cell studies showed over 90% viability for Chit/Col film + PVA/AMX nanofiber hybrid bilayer membranes, confirming their biocompatibility. The antimicrobial assessment indicated that the Chit/Col film + PVA/AMX (0.2%) nanofiber hybrid bilayer membrane exhibited superior efficacy against Streptococcus mutans. These findings suggest that this hybrid bilayer membrane can enhance cell growth, promote proliferation, and enable controlled drug release, offering significant promise for regeneration of gingival tissues.

Dynamic-Covalent Mesoporous Silica Nanohybrid with pH/ROS-Responsive Drug Release for Targeted Tumor Therapy

Dynamic-Covalent Mesoporous Silica Nanohybrid with pH/ROS-Responsive Drug Release for Targeted Tumor Therapy

Synthetic Biology-Enabled Engineering of Probiotics for Precision and Targeted Therapeutic Delivery Applications

Probiotics, defined as live microorganisms that offer health benefits when consumed in adequate amounts, have traditionally been used to maintain gastrointestinal (GI) health. They are effective in managing conditions such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and antibiotic-associated diarrhea. Recent research, however, has expanded their potential applications beyond the GI tract to include immune modulation, metabolic regulation, and mental health support. Despite these advances, conventional probiotics face limitations such as instability in harsh environments, lack of precise targeting, and ineffective control over drug release. This review explores the application of synthetic biology in addressing these limitations, emphasizing how tools such as CRISPR-Cas systems, synthetic gene circuits, and plasmid-based mechanisms enhance the stability, functionality, and specificity of engineered probiotics for therapeutic delivery. Applications of synthetic biology-enabled probiotics are examined across a range of health contexts, including GI health, cancer therapy, metabolic disorders, immune modulation, and mental well-being. Synthetic biology tools provide precise genetic modifications that improve the stability, viability, and functionality of engineered probiotics, enabling more targeted therapeutic delivery. Additionally, technologies such as encapsulation support probiotic survival, while gene circuits allow programmable, stimulus-responsive therapeutic release. As synthetic biology continues to advance, the development of programmable probiotics holds promise for personalized, targeted medicine, positioning probiotics as living therapeutics and patient-friendly alternatives to conventional therapeutic delivery systems.

Development, QbD-based optimisation, in-vivo pharmacokinetics, and ex-vivo evaluation of Eudragit® RS 100 loaded flurbiprofen nanoparticles for oral drug delivery.

This study aims to develop and evaluate flurbiprofen-loaded polymeric nanoparticles to achieve sustained drug release, enhancing therapeutic efficacy and minimising dosing frequency for improved patient outcomes. Flurbiprofen-loaded polymeric nanoparticles were prepared using a tubular microreactor and spray drying, optimised via Box-Behnken Design. Characterisation included particle size, encapsulation efficiency, in vitro and in vivo drug release, and techniques like FTIR, DSC, XRD, and SEM. Statistical analysis ensured robust formulation optimisation and evaluation of performance. The optimised batch of flurbiprofen-loaded polymeric nanoparticles was characterised for mean diameter, PDI, zeta potential, drug release, and EE% were found to be 306.1 ± 6.00 nm, 0.184 ± 0.02 Mw, -23.6 ± 1.51 mV, 85.46 ± 0.53% and 92.31 ± 0.84 (% w/w) respectively. Pharmacokinetic analysis further confirmed the sustained release, extending up to 12 hours and enhancing permeation compared to the pure flurbiprofen. Sustained release of flurbiprofen-loaded polymeric nanoparticles significantly enhances therapeutic effectiveness for inflammatory conditions.

Formulation, Development and Evaluation of Pulsatile Tablets of Etoricoxib

Aim: This research aimed to develop a pulsatile drug delivery system (PDDS) for etoricoxib, selective COX-2 inhibitor analgesic, to address the limitations of conventional formulations by releasing the drug at specific intervals aligned with the circadian rhythm of pain. Method: Core tablets containing Etoricoxib were prepared by direct compression with varied concentrations of croscarmellose sodium as a superdisintegrant. The optimized core tablets were coated using hydrophilic (HPMC K4M) and hydrophobic (ethyl cellulose) polymers in different ratios to create press-coated pulsatile tablets with varying lag times. Physical properties hardness, thickness, friability, and disintegration, drug content uniformity, and in vitro release were evaluated. Results: The core tablets exhibited rapid drug release, with batch C3 showing 98.61% release within 60 minutes. Press-coated formulations with different polymer ratios exhibited varying lag times, with batch F3 achieving the optimal balance—providing a 4-hour lag time and 96.6% drug release over 8 hours. Stability studies confirmed the physical and chemical stability of the optimized formulation (F3) over 6 months under accelerated conditions. Conclusion: The developed press-coated pulsatile tablets of etoricoxib successfully achieved a controlled lag time and sustained drug release profile, making them suitable for chronopharmacological management of pain. Keywords: Etoricoxib, Pulsatile Drug Delivery System, Chronopharmacology, Press-Coated Tablets. etc

Formulation and Evaluation of Mucoadhesive Buccal Tablets of Carvedilol

The aim of the study was to formulate and evaluate the carvedilol buccal tablets using HPMC K4M and xanthan gum as polymer. Buccal tablets of carvedilol were prepared by direct compression technique by using polymer in combination at different concentration. Drug excipient compatibility study indicates that there is no interaction between the excipient and the drug. Total seven batches were prepared and subjected to evaluation parameters. Pre-compression parameters for all batches showed excellent flow propertied of powder bled. Prepared buccal tablets were evaluated for various post compression parameters like hardness, thickness, weight variation, drug content, and friability, % swelling index, muco-adhesive strength and in vitro drug release. The harness of all batches was optimum showed good mechanical strength; thickness of tablets was uniform in all formulations the weight variation test of all the formulation was found to be within the limits of pharmacopoeial standard. % swelling index for all the batch formulation was optimum and seen to increase with increase in polymer concentration. Mucoadhesive strength was also showed acceptable results for all batch formulations which satisfy the need of mucoadhesive tablets. The in vitro dissolution profile of all the formulation showed sustained release of drug, for extended periods of time. The optimized formulation of F4 prepared with was consider as the optimized formulation with respect to drug content, % swelling index, Mucoadhesive strength and in vitro drug release pattern for 8 hrs. Formulation F4 showed highest 98.32±1.55 % drug release at the end of 8 hrs. Optimized formulation F4 was found to be stable during the stability studies for 3 month indicating good stability of the formulation. Keywords: carvedilol, Mucoadhesive strength, Optimized formulation, buccal tablets.

Timolol Maleate Microspheres: An Ingenious Carrier for Sustained Release Antihypertensive Formulation

Background: Timolol maleate is classified as a BCS Class I drug and functions as a non-selective β-adrenergic receptor blocker. Its ability to lower heart rate and cardiac output has led to its widespread use in the treatment of hypertension. Objective: Timolol maleate has a short half-life and is rapidly cleared from the body, which limits its therapeutic effectiveness, requiring frequent dosing and potentially affecting patient adherence. To overcome these challenges, sustained-release microspheres of Timolol maleate were developed using the ion gelation method. Method: The ion gelation technique was employed to create the microspheres due to its various advantages, including ease of use, scalability and gentle processing conditions. Results: All batches exhibited a comparatively lower swelling index in 0.1M HCl (pH 1.2) than in SIF (pH 6.8). It was observed that increasing the concentration of sodium alginate resulted in higher drug content. The microspheres were sized between 400 and 900 μm and demonstrated excellent flow characteristics. An optimized batch achieved an entrapment efficiency of 88.83% and released 92.15% of the drug over 7 hrs. Furthermore, stability studies conducted according to ICH Q1A(R2) for 3 months at 5±3°C and 25±2°C/60±5% RH indicated no significant changes in evaluation parameters. Conclusion: The optimized Timolol maleate-loaded microspheres effectively provided sustained drug release through the membrane over 7 hrs. This study contributes to the development of improved drug delivery systems for better hypertension management, addressing the unmet needs in patient compliance. Keywords: Timolol Maleate, Microspheres, Ion gelation method, Sodium alginate, Calcium chloride, Sustained release, Hypertension

ENHANCING TRANSDERMAL DELIVERY OF POORLY WATER-SOLUBLE NSAIDS: EFFECTIVE STRATEGIES

Transdermal drug delivery offers significant advantages for administering non-steroidal anti-inflammatory drugs (NSAIDs) and anti-complementary drugs, particularly those with poor water solubility. This delivery route bypasses first-pass metabolism and gastrointestinal degradation, enhancing bioavailability and patient compliance. However, the stratum corneum, the outermost layer of the skin, poses a formidable barrier to drug permeation. To address this challenge, several innovative strategies have been developed to improve the transdermal delivery of these poorly soluble drugs. Chemical enhancers, such as alcohols, fatty acids, and surfactants, can disrupt the lipid structure of the stratum corneum, increasing drug solubility and permeability. Nanoformulations, including liposomes, niosomes, solid lipid nanoparticles, and nanoemulsions, enhance drug solubility, provide protection against degradation, and facilitate controlled release with deeper skin penetration. Prodrugs, designed to convert into the active drug within the skin, can improve solubility and permeability. Physical methods like microneedles, iontophoresis, and phonophoresis create micropores or use electrical and ultrasound waves to enhance permeation without compromising skin integrity. Cyclodextrins form inclusion complexes with drugs, boosting solubility and stability. Hydrogels and polymer-based formulations create a moist environment for sustained drug release and better absorption. Co-solvents and surfactants, such as ethanol and DMSO, further enhance solubility and disrupt the stratum corneum to facilitate drug penetration. Electroporation and thermal ablation transiently disrupt the skin barrier, significantly improving drug permeation. These strategies, individually or in combination, hold promise for optimizing the transdermal delivery of poorly water-soluble NSAIDs and anticomplementary drugs, ensuring effective therapeutic outcomes and improved patient compliance.

Magnetic hydrogel scaffold based on hyaluronic acid/chitosan and gelatin natural polymers.

Owing to their native extracellular matrix-like features, magnetic hydrogels have been proven to be promising biomaterials as tissue engineering templates In the present work, magnetic hydrogels scaffold based on chitosan, gelatin, hyaluronic acid, containing Fe3O4 as magnetic nanoparticles (IONPs) were prepared. The prepared hydrogels were loaded with ciprofloxacin hydrochloride as a model drug. The magnetic hydrogel was prepared using different volumes of chitosan, 1%, gelatin, 10%, and hyaluronic acid, 1% in glutaraldehyde as the crosslinking agent and Fe3O4 as magnetic nanoparticles. The hydrogel scaffold and magnetic scaffold hydrogel samples were characterized by scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), and Fourier-transform infrared spectroscopy (FTIR). The porosity, mechanical properties, swelling degree, and antibacterial activity of the hydrogel scaffold were also determined as well as the drug release profiles of the hydrogels. SEM imaging revealed that the magnetic hydrogel scaffold showed a relatively rough morphology with an irregular surface. The data obtained indicated that the hydrogel surface has three-dimensional porous microstructures and the porosity varied depending on the hydrogel formulation. The breaking load of the hydrogel scaffold increased from 1.361 Kgf to 4.98 Kgf by increasing the glutaraldehyde concentration from 0.2 mL to 0.8 mL. Swelling degree values in water were from 250 to 2000% after 24h. The antibacterial activity of the hydrogel scaffold ranged from 54% to about 97% for Gram-positive bacteria (S. aureus) and from about 26-92% for Gram-negative bacteria (E. coli). The ciprofloxacin hydrochloride loaded hydrogel has a sustained release of ciprofloxacin hydrochloride over 10h. The presence of IONPs gave a faster release of ciprofloxacin hydrochloride.

Advances in Green Synthesis of Silver Nanoparticles: Sustainable Approaches and Applications

In the rapidly evolving field of nanotechnology, the synthesis of silver nanoparticles (AgNPs) has shifted towards eco-friendly methodologies, aligning with the growing demand for sustainable practices. Biologically synthesized AgNPs, particularly noteworthy for their applications in medicine and materials science, exhibit exceptional efficacy against microorganisms. The unique physicochemical properties of AgNPs, including their small size and large surface area-to-volume ratio, contribute to their versatility in diverse sectors. The advantages of AgNPs, such as ease of production, low cost, and high carrier capacity, make them preferred for various applications, including drug delivery systems. Despite concerns about environmental hazards and toxicity, the benefits of AgNPs, such as controlled drug release and targeted delivery, position them as valuable contributors to advancements in nanotechnology. Green synthesis methods, emphasizing biological processes and natural compounds, gain prominence for their sustainability and reduced environmental impact. The regulatory oversight of nanoproducts ensures their safe use, balancing their advantages with environmental considerations. Ongoing research promises further innovations, solidifying AgNPs' role as key contributors to progress in nanotechnology and materials science. Keywords: Silver nanoparticles, Green synthesis, Sustainable approaches, Characterization, Applications, Eco-friendly methods.

Drug release kinetics from in-situ modulated agar/chitosan-bacterial cellulose patches for differently soluble drugs.

Bacterial cellulose (BC) stands out as a promising candidate for novel drug delivery systems due to its micro-mesoporous nanofibrous interconnected structure. However, its performance is limited by the burst release of hydrophilic drugs and lower incorporation of the less water-soluble or insoluble drugs. In this study, we explored its potential as a drug carrier for two distinct types of drugs: Diclofenac sodium and Simvastatin, representing water-soluble and water insoluble compounds, respectively. To tune the morphology and drug-BC interaction, agar and chitosan were introduced into the culture medium during BC synthesis for in-situ modification. These modulated BCs are characterized and further analyzed through drug release studies and mathematical modeling to understand the mechanisms and key factors controlling the drug release behavior. Incorporating agar and chitosan into the BC network results in changes to its microstructure and crystallinity, which in turn affects the overall swelling, drug loading and release properties. Our results revealed that the BC followed a first-order quasi-Fickian kinetics for water-soluble drug and non-Fickian release mechanism for water-insoluble drug. In contrast, agar-modulated BC (A-MBC) demonstrated a non-Fickian first-order diffusion kinetics, with slow release for water-soluble drug and sustained release for the water-insoluble drug due to the higher density which impedes drug release. Chitosan-modulated BC (C-MBC) exhibited non-Fickian first-order kinetics, with slower release for water soluble drug. Further, C-MBC exhibited extended release for water insoluble drug to over 14 days, following first-order kinetics for the first 12 h, then transitioning to zero-order kinetics with a Case II release mechanism, attributed to drug-matrix interactions. These findings successfully demonstrate the possibility to tailor BC thus the release kinetics for both water-soluble and less soluble or insoluble drugs.

Preparation and characterization of poly(ethylene glycol)-b-poly(tert-butyl methacrylate) micelles as potential nanocarriers for donepezil

Polymeric micelles were prepared for the delivery of donepezil, a leading Alzheimer’s disease drug, to enhance its transport across the blood–brain barrier (BBB). Poly(ethylene glycol)-b-poly(tert-butyl methacrylate) amphiphilic block copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were characterized by gel permeation chromatography and nuclear magnetic resonance spectroscopy. Empty and donepezil loaded polymer micelles were formed using the dialysis method and characterized by dynamic light scattering and transmission electron microscopy. Drug loading efficiency and release behavior were monitored using UV/Vis spectroscopy, and cytotoxicity was evaluated via colorimetric tests and impedance measurements. Additionally, the permeability of the nanocarriers across an in vitro BBB culture model was assessed. Drug-loaded micelles demonstrated similar permeability to free donepezil but offered sustained release and improved stability. This micellar delivery system holds significant potential for improving therapeutic outcomes in Alzheimer’s treatment by enhancing donepezil’s delivery across the BBB. Improved BBB permeability and sustained drug release could lead to more effective concentration of the drug in the brain, potentially reducing peripheral cholinergic side effects, such as nausea and vomiting, often observed with traditional donepezil administration. This could result in better patient compliance and improved cognitive outcomes, making this nanocarrier system a promising alternative for Alzheimer’s therapy.

A Novel Concept for Cleavable Linkers Applicable to Conjugation Chemistry - Design, Synthesis and Characterization.

Linkers with disulfide bonds are the only cleavable linkers that utilize physiological thiol gradients as a trigger to initiate the intracellular drug release cascade. Herein, we present a novel concept exploiting the thiol gradient phenomena to design a new class of cleavable linker with no disulfide bond. To support the concept, an electron-deficient sulfonamide-based cleavable linker amenable to conjugation of drug molecules with targeting agents, was developed. Modulating the electron-withdrawing nature of the aryl sulfonamide was critical to the balance between the stability and drug release. Favorable stability and payload release in human serum under physiologically relevant thiol concentrations was demonstrated with two potent cytotoxics. Intracellular payload release was further validated in cell-based assay in context of antibody-drug conjugate generated from monoclonal antibody and sulfonamide containing linker. To support the proposed release mechanism, possible downstream by-products formed from the drug-linker adduct were characterized.

Aqueous Dispersion Polymerization for the Development of Lamivudine-Polyacrylonitrile Nanoparticles through Quality by Design Approach.

The development of polymeric nanoparticles (NPs) from preformed polymers usually requires the use of organic solvents and is more expensive. Hence, in this work, the development of polymeric nanoparticles by in situ aqueous dispersion polymerization from the monomers was set as an objective. Acrylonitrile monomer based polymeric NPs comprising Lamivudine (LMV) as a model drug were prepared using the aqueous dispersion polymerization technique. A quality by design approach was applied to optimise various formulation and process factors viz. monomer concentration, initiator concentration, stabilizer concentration and polymerization temperature. Polymerization time (PT), entrapment efficiency (EE), particle size (PS), and drug release rate constant (k) were taken as the responses to define the quality of the prepared NPs. Design of experiments analysis followed by optimization was performed to identify the optimized combination of the factors. Later, the optimized formulation was studied for the physical state of the LMV in the nanoparticles, surface morphology of the NPs and cytotoxicity studies. The optimized formulation was found to have 91.7 min. of PT, 81.4% of EE, 253 nm of PS and a k value of 0.262 h-1 (18 h to release 99%). The cytotoxicity studies indicated that the NPs were highly safe to use. These results altogether inferred that LMV contained NPs were developed effectively from the acrylonitrile monomer by the aqueous dispersion polymerization method.

Complex interplay between the microfluidic and optical properties of Hoplia sp. beetles.

All living organisms exist in a world affected by many external influences, especially water and light. Photonic nanostructures present in certain insects, have evolved over time in response to diverse environmental conditions, facilitating communication within and between species, camouflage, thermoregulation, hydration, and more. Up to now, only a few insect species have been discovered whose elytron changes its color due to permeation of water (or its vapor) through cuticle. Here we report on a scarabaeid beetle Hoplia argentea remarkable in its ability to shift from green to brownish-red when exposed to water, demonstrating reversible changes. Here we show that elytron and scales form a complex and efficient micro/nano-optofluidic system. Water is channeled into the elytral lacunae, then transported internally to the petals of the scales, where it is wicked inside each scale, pushing the entrapped air out. Wicking is a very fast process, occurring during a few seconds. The advantage of this principle is in extremely high pressure (approximately 15bar) produced by capillary forces, which expediates permeation of air. We present optical models that explain the physical mechanisms behind the coloration, detailing how superhydrophilic properties influence optical behavior. Species within the genus Hoplia exhibit diverse coloration strategies, likely linked to their specific ecological niches. These organisms have evolved intricate optical and microfluidic systems that facilitate rapid alterations in body coloration, potentially serving purposes such as environmental camouflage and thermoregulation. Studying microfluidic and optical properties of the elytra will not only enhance our understanding of the biological purposes behind color change but also inspires design of artificial biomimetic devices. Dynamic fluid flow patterns, described in this paper, are fairly constant and unique and can be used in security applications as a, so called, physically unclonable functions (PUF). More broadly, this kind of microfluidic system can be used for controlled drug release, sensing, hydraulic and pneumatic pumping.

Advances in Transdermal Drug Delivery: The Development of Microneedle Technology for Improved Therapeutic Outcomes

Transdermal Drug Delivery Systems (TDDS) represent a significant advancement in therapeutic administration by allowing drugs to bypass the gastrointestinal system and first-pass hepatic metabolism, enhancing patient compliance, and enabling sustained drug release. However, traditional TDDS face limitations, including resistance from the skin's natural barrier and limited efficacy in delivering large or hydrophilic molecules. Microneedle (MN) technology offers a breakthrough solution, using minimally invasive micron-sized needles to bypass the stratum corneum, facilitating efficient drug delivery without significant pain or discomfort. This review explores the evolution and recent advancements in microneedle technology, highlighting its role in overcoming the limitations of conventional TDDS. Microneedles have been shown to enhance drug bioavailability, reduce side effects, and expand the range of deliverable therapeutics, including vaccines, insulin, and genetic materials. The development of bioinspired 4D microneedles further extends their application to diagnostics and cosmetic treatments, positioning MNs as a versatile tool in modern medicine. Key sections of the review focus on the types of microneedles—solid, coated, dissolving, hollow, and hydrogel-forming—and their respective fabrication methods, materials, and drug delivery mechanisms. The review also discusses the challenges related to scaling up production, ensuring consistent quality, and regulatory hurdles in achieving clinical approval. Future directions include the integration of microneedles with nanotechnology, combination therapies, and sustainable design, particularly in developing regions where biodegradable materials may address environmental and disposal concerns. The potential for microneedle technology to revolutionize transdermal drug delivery, diagnostics, and therapeutic monitoring is significant, with ongoing research paving the way for multifunctional applications that can reshape patient care and treatment modalities.

β-d-Ribofuranose as a Core with a Phosphodiester Moiety as the Enzyme Recognition Site for Codrug Development.

An ideal codrug design should be able to control drug release, offer selectivity during drug delivery, and break down into non-toxic fragments after biodegradation. Our design incorporates d-ribofuranose as the core, with carbamate and carbonate groups as linking joints, a phosphodiester moiety as an enzyme recognition site, and lenalidomide and paclitaxel as the constituent drugs. The codrug synthesis involves seven steps with a 33% overall yield. The target codrug increases its water solubility 685 times versus paclitaxel.

PH-responsive AIE nanogels for synergistic chemo-photodynamic cancer therapy with imaging guidance

Abstract Photodynamic therapy (PDT) is a promising cancer treatment that uses photosensitizers (PSs) to generate cytotoxic reactive oxygen species (ROS) under light, but improving its efficacy is crucial for clinical applications. To address this, we propose a smart nanoplatform (P@BAO-DOX) for synergistic chemo-photodynamic therapy, featuring efficient PDT, controllable drug release, and fluorescence imaging guidance. We designed an aggregation-induced emission (AIE)-based PS (BAO) with effective ROS generation and NIR-II fluorescence. Additionally, BAO as a PS and doxorubicin (DOX) as a chemo drug were encapsulated in pH-responsive nanogels (PNA) to obtain P@BAO-DOX nanogels. Upon uptake by tumor cells, the nanogel releases drugs in acidic conditions, leading to cell death. White light irradiation further triggers BAO to produce substantial ROS, enhancing phototoxicity and synergistic chemo-PDT cancer therapy. Thus, P@BAO-DOX nanogels, as a smart nanoplatform, offer precise drug release and efficient ROS generation for imaging-guided chemo-PDT synergistic therapy, showing promise in advancing cancer treatment.

Microfluidic Fabrication of Oleosin-Coated Liposomes as Anticancer Drug Carriers with Enhanced Sustained Drug Release

Microfluid-derived liposomes (M-Lipo) exhibit great potential as drug and functional substance carriers in pharmaceutical and food science. However, the low liposome membrane stability, attributed to the liquid core, limits their application range. Oleosin, a natural surfactant protein, can improve the stability of the lipid nanoparticle membrane against various environmental stresses, such as heat, drying, and pH change; in addition, it can enable sustained drug release. Here, we proposed the fabrication of oleosin-coated M-Lipo (OM-Lipo) through self-assembly on a microfluidic chip and the evaluation of its anticancer drug (carmustine) delivery efficiency. Nanoparticle characterization revealed that the oleosin coating slightly lowered the membrane potential of M-Lipo and greatly improved their dispersibility. Additionally, the in vitro drug release profile showed that the oleosin coating improved the sustained release of the hydrophobic drug from the phospholipid bilayer in body temperature. Our results suggest that OM-Lipo has sufficient potential in various fields, based on its easy production, excellent stability, and biocompatibility.

Cysteine Conjugation: An Approach to Obtain Polymers with Enhanced Muco- and Tissue Adhesion

The modification of polymers towards increasing their biocompatibility gathers the attention of scientists worldwide. Several strategies are used in this field, among which chemical post-polymerization modification has recently been the most explored. Particular attention revolves around polymer-L-cysteine (Cys) conjugates. Cys, a natural amino acid, contains reactive thiol, amine, and carboxyl moieties, allowing hydrogen bond formation and improved tissue adhesion when conjugated to polymers. Conjugation of Cys and its derivatives to polymers has been examined mostly for hyaluronic acid, chitosan, alginate, polyesters, polyurethanes, poly(ethylene glycol), poly(acrylic acid), polycarbophil, and carboxymethyl cellulose. It was shown that the conjugation of Cys and its derivatives to polymers significantly increased their tissue adhesion, particularly mucoadhesion, stability at physiological pH, drug encapsulation efficiency, drug release, and drug permeation. Conjugates were also non-toxic toward various cell lines. These properties make Cys conjugation a promising strategy for advancing polymer applications in drug delivery systems and tissue engineering. This review aims to provide an overview of these features and to present the conjugation of Cys and its derivatives as a modern and promising approach for enhancing polymer tissue adhesion and its application in the medical field.