A review on albumin as a biomaterial for ocular drug delivery

Nanomedicine in glaucoma treatment; Current challenges and future perspectives

Glaucoma presents a significant global health concern and affects millions of individuals worldwide and predicted a high increase in prevalence of about 111 million by 2040. The current standard treatment involves hypotensive eye drops; however, challenges such as patient adherence and limited drug bioavailability hinder the treatment effectiveness. Nanopharmaceuticals or nanomedicines offer promising solutions to overcome these obstacles. In this manuscript, we summarized the current limitations of conventional antiglaucoma treatment, role of nanomedicine in glaucoma treatment, rational design, factors effecting the performance of nanomedicine and different types of nanocarriers in designing of nanomedicine along with their applications in glaucoma treatment from recent literature. Current clinical challenges that hinder real-time application of antiglaucoma nanomedicine are highlighted. Lastly, future directions are identified for improving the therapeutic potential and translation of antiglaucoma nanomedicine into clinic.

Boosting Checkpoint Immunotherapy with Biomimetic Nanodrug Delivery Systems

Immune checkpoint blockade (ICB) has achieved unprecedented progress in tumor immunotherapy by blocking specific immune checkpoint molecules. However, the high biodistribution of the drug prevents it from specifically targeting tumor tissues, leading to immune-related adverse events. Biomimetic nanodrug delivery systems (BNDSs) readily applicable to ICB therapy have been widely developed at the preclinical stage to avoid immune-related adverse events. By exploiting or mimicking complex biological structures, the constructed BNDS as a novel drug delivery system has good biocompatibility and certain tumor-targeting properties. Herein, the latest findings regarding the aforementioned therapies associated with ICB therapy are highlighted. Simultaneously, prospective bioinspired engineering strategies can be designed to overcome the four-level barriers to drug entry into lesion sites. In future clinical translation, BNDS-based ICB combination therapy represents a promising avenue for cancer treatment.

Biomaterials for Protein Delivery: Opportunities and Challenges to Clinical Translation

The development of biomaterials for protein delivery is an emerging field that spans materials science, bioengineering, and medicine. In this review, we highlight the immense potential of protein-delivering biomaterials as therapeutic options and discuss the multifaceted challenges inherent to the field. We address current advancements and approaches in protein delivery that leverage stimuli-responsive materials, harness advanced fabrication techniques like 3D printing, and integrate nanotechnologies for greater targeting and improved stability, efficacy, and tolerability profiles. We also discuss the demand for highly complex delivery systems to maintain structural integrity and functionality of the protein payload. Finally, we discuss barriers to clinical translation, such as biocompatibility, immunogenicity, achieving reliable controlled release, efficient and targeted delivery, stability issues, scalability of production, and navigating the regulatory landscape for such materials. Overall, this review summarizes insights from a survey of the current literature and sheds light on the interplay between innovation and the practical implementation of biomaterials for protein delivery.

Nose-to-brain delivery of nanotherapeutics: Transport mechanisms and applications

The blood-brain barrier presents a key limitation to the administration of therapeutic molecules for the treatment of brain disease. While drugs administered orally or intravenously must cross this barrier to reach brain targets, the unique anatomical structure of the olfactory system provides a route to deliver drugs directly to the brain. Entering the brain via receptor, carrier, and adsorption-mediated transcytosis in the nasal olfactory and trigeminal regions has the potential to increase drug delivery. In this review, we introduce the physiological and anatomical structures of the nasal cavity, and summarize the possible modes of transport and the relevant receptors and carriers in the nose-to-brain pathway. Additionally, we provide examples of nanotherapeutics developed for intranasal drug delivery to the brain. Further development of nanoparticles that can be applied to intranasal delivery systems promises to improve drug efficacy and reduce drug resistance and adverse effects by increasing molecular access to the brain. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease.

Therapeutic Potential Evaluation of Silk Sericin Stabilized Fisetin to Ulcerative Colitis

Ulcerative colitis is a chronic inflammatory bowel disease with a high recurrence rate. Natural phytochemical compounds are increasingly being considered as preventative and supportive treatments for this condition. However, the poor water solubility and stability of many of these compounds limit their effectiveness in vivo. To address this issue, fisetin (FT), a natural phytochemical with poor solubility, is stabilized using silk sericin (SS) to create a composite (SS/FT). The therapeutic potential of the SS/FT on ulcerative colitis is extensively investigated, and the results showed that it effectively alleviated the body weight loss and colon length shortening induced by dextran sulfate sodium. Notably, SS/FT downregulated the immune response, decreased colonic histopathological lesions, and reduced the cGAS/STING signal activation. This suggests that SS/FT may offer a promising therapy for treating ulcerative colitis.

Advanced Drug Carriers: A Review of Selected Protein, Polysaccharide, and Lipid Drug Delivery Platforms

Studies on bionanocomposite drug carriers are a key area in the field of active substance delivery, introducing innovative approaches to improve drug therapy. Such drug carriers play a crucial role in enhancing the bioavailability of active substances, affecting therapy efficiency and precision. The targeted delivery of drugs to the targeted sites of action and minimization of toxicity to the body is becoming possible through the use of these advanced carriers. Recent research has focused on bionanocomposite structures based on biopolymers, including lipids, polysaccharides, and proteins. This review paper is focused on the description of lipid-containing nanocomposite carriers (including liposomes, lipid emulsions, lipid nanoparticles, solid lipid nanoparticles, and nanostructured lipid carriers), polysaccharide-containing nanocomposite carriers (including alginate and cellulose), and protein-containing nanocomposite carriers (e.g., gelatin and albumin). It was demonstrated in many investigations that such carriers show the ability to load therapeutic substances efficiently and precisely control drug release. They also demonstrated desirable biocompatibility, which is a promising sign for their potential application in drug therapy. The development of bionanocomposite drug carriers indicates a novel approach to improving drug delivery processes, which has the potential to contribute to significant advances in the field of pharmacology, improving therapeutic efficacy while minimizing side effects.

In situ vaccination via tissue-targeted cDC1 expansion enhances the immunogenicity of chemoradiation and immunotherapy

Even with the prolific clinical use of next-generation cancer therapeutics, many tumors remain unresponsive or become refractory to therapy, creating a medical need. In cancer, DCs are indispensable for T cell activation, so there is a restriction on cytotoxic T cell immunity if DCs are not present in sufficient numbers in the tumor and draining lymph nodes to take up and present relevant cancer antigens. To address this bottleneck, we developed a therapeutic based on albumin fused with FMS-related tyrosine kinase 3 ligand (Alb-Flt3L) that demonstrated superior pharmacokinetic properties compared with Flt3L, including significantly longer half-life, accumulation in tumors and lymph nodes, and cross-presenting-DC expansion following a single injection. We demonstrated that Alb-Flt3L, in combination with standard-of-care chemotherapy and radiation therapy, serves as an in situ vaccination strategy capable of engendering polyclonal tumor neoantigen-specific immunity spontaneously. In addition, Alb-Flt3L-mediated tumor control synergized with immune checkpoint blockade delivered as anti-PD-L1. The mechanism of action of Alb-Flt3L treatment revealed a dependency on Batf3, type I IFNs, and plasmacytoid DCs. Finally, the ability of Alb-Flt3L to expand human DCs was explored in humanized mice. We observed significant expansion of human cross-presenting-DC subsets, supporting the notion that Alb-Flt3L could be used clinically to modulate human DC populations in future cancer therapeutic regimens.

Recent advances in nanotechnology for the treatment of fungal keratitis

Fungal keratitis (FK) is a serious pathogenic disease usually associated with serious ocular complications. The current mainstay of treatment for FK is topical eye drops; however, poor corneal penetration, low bioavailability of the drug and the need to administer high and frequent doses due to the presence of an effective clearance mechanism in the eye result in poor patient compliance. Nanocarriers can extend the duration of drug action through sustained and controlled release of the drug, protect the drug from ocular enzymes and help overcome ocular barriers. In this review, we discussed the mechanisms of action of antifungal drugs, the theoretical basis for the treatment of FK, and recent advances in the clinical treatment of FK. We have summarized the results of research into the most promising nanocarriers for ocular drug delivery and highlight their efficacy and safety in the therapy.

Disruption of Iron Homeostasis to Induce Ferroptosis with Albumin-Encapsulated Pt(IV) Nanodrug for the Treatment of Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most common pathological type of lung cancer , accounting for approximately 85% of lung cancers. For more than 40 years, platinum (Pt)-based drugs are still one of the most widely used anticancer drugs even in the era of precision medicine and immunotherapy. However, the clinical limitations of Pt-based drugs, such as serious side effects and drug resistance, have not been well solved. This study constructs a new albumin-encapsulated Pt(IV) nanodrug (HSA@Pt(IV)) based on the Pt(IV) drug and nanodelivery system. The characterization of nanodrug and biological experiments demonstrate its excellent drug delivery and antitumor effects. The multi-omics analysis of the transcriptome and the ionome reveals that nanodrug can activate ferroptosis by affecting intracellular iron homeostasis in NSCLC. This study provides experimental evidence to suggest the potential of HSA@Pt(IV) as a nanodrug with clinical application.

Role of Albumin as a Targeted Drug Carrier in the Management of Rheumatoid Arthritis: A Comprehensive Review

An endogenous transporter protein called albumin interacts with the Fc receptor to provide it with multiple substrate-binding domains, cell membrane receptor activation, and an extended circulating half-life. Albumin has the remarkable ability to bind with receptors viz. secreted protein acidic and rich in cysteine (SPARC) and scavenger protein-A (SR-A) that are overexpressed during rheumatoid arthritis (RA), enabling active targeting of the disease site instead of requiring specialized substrates to be added to the nanocarrier. RA, a chronic autoimmune illness, is characterized by the presence of a severe inflammatory response. RA patients have low serum albumin concentration, which signifies the high uptake of albumin at the inflammatory sites, giving a rationale to use albumin as a drug carrier for RA therapy. Albumin has the capacity for both passive and active targeting. It is an abundantly available protein in the bloodstream showing excellent cellular compatibility, degradability in biological tissues, nonantigenicity, and safety. There are three strategies of albumin mediated drug delivery as encapsulating therapeutics in albumin nanoparticles, chemically conjugating drugs with functional proteins, and albumin itself which is used as a targeting ligand to deliver drugs specifically to cells or tissues that express albumin-binding receptors. In the current review, an attempt has been made to highlight the significant evidence of albumin as a drug delivery carrier for the safe and effective management of RA. Evidence has been provided in the form of recent research advances, clinical trials, and patents. Additionally, this review will outline the prospective for the potential utilization of albumin as a drug vehicle for RA and suggest possible future avenues to provide the perspective for subsequent studies.

Polymeric micelles loaded in situ gel with prednisolone acetate for ocular inflammation: development and evaluation

Aim: Our study developed a prednisolone acetate polymeric micelles (PM) system for ocular inflammation related to allergic uveitis. Methods: For PM development, a thin-film hydration procedure was used. Irritation, in vitro, ex vivo transcorneal permeation, micelle size, entrapment efficiency and histology within the eye were all calculated for PM. Results: The optimized in situ gel (A4) showed superior ex vivo transcorneal permeation with zero-order kinetics. Conclusion: The developed formulation could be a promising candidate for treating anterior uveitis via topical application to the anterior segment of the eye.

Exploring Penetration Ability of Carbonic Anhydrase Inhibitor-Loaded Ultradeformable Bilosome for Effective Ocular Application

Brinzolamide is an effective carbonic anhydrase inhibitor widely used in glaucoma therapy but limits its application due to inadequate aqueous solubility and permeability. The aim of the present research work is the development and characterization of brinzolamide-loaded ultradeformable bilosomes to enhance the corneal permeation of the drug. These ultradeformable bilosomes were prepared by ethanol injection method and evaluated for physicochemical properties, particle size, morphology, drug release, ultra-deformability, corneal permeation, and irritation potential. The optimized formulation exhibited an average particle size of 205.4 ± 2.04 nm with mono-dispersity (0.109 ± 0.002) and showed entrapment efficiency of 75.02 ± 0.017%, deformability index of 3.91, and release the drug in a sustained manner. The brinzolamide-loaded ultradeformable bilosomes released 76.29 ± 3.77% of the drug in 10 h that is 2.25 times higher than the free drug solution. The bilosomes were found non-irritant to eyes with a potential irritancy score of 0 in Hen's egg-chorioallantoic membrane assay. Brinzolamide-loaded ultradeformable bilosomes showed 83.09 ± 5.1% of permeation in 6 h and trans-corneal permeability of 8.78 ± 0.14 cm/h during the ex vivo permeation study. The acquired findings clearly revealed that the brinzolamide-loaded ultradeformable bilosomes show promising output and are useful in glaucoma therapy.

Biomaterial Drug Delivery Systems for Prominent Ocular Diseases

Ocular diseases, such as age-related macular degeneration (AMD) and glaucoma, have had a profound impact on millions of patients. In the past couple of decades, these diseases have been treated using conventional techniques but have also presented certain challenges and limitations that affect patient experience and outcomes. To address this, biomaterials have been used for ocular drug delivery, and a wide range of systems have been developed. This review will discuss some of the major classes and examples of biomaterials used for the treatment of prominent ocular diseases, including ocular implants (biodegradable and non-biodegradable), nanocarriers (hydrogels, liposomes, nanomicelles, DNA-inspired nanoparticles, and dendrimers), microneedles, and drug-loaded contact lenses. We will also discuss the advantages of these biomaterials over conventional approaches with support from the results of clinical trials that demonstrate their efficacy.

Novel Nanotherapeutics for Cancer Immunotherapy by PD-L1-Aptamer-Functionalized and Fexofenadine-Loaded Albumin Nanoparticles

Immune checkpoint blockade (ICB) is an important strategy for cancer treatment and has achieved remarkable clinical results. Further enhancement of the efficacy of ICB therapy with a new technical approach is of potential medical importance. In this study, we constructed a novel nanotherapeutic agent (PDL1-NP-FEXO) for cancer immunotherapy by attaching PD-L1 aptamers to albumin nanoparticles that were loaded with H1-antihitamine fexofenadine (FEXO). FEXO has been reported to enhance the immunotherapy response by reducing the immunosuppressive M2-like macrophages in the tumor microenvironment. The albumin nanoparticle was fabricated using a self-assembly method. A dynamic light scattering (DLS) study revealed that the average size of PD-L1 aptamer-modified nanoparticle without FEXO (PDL1-NP) was 135.5 nm, while that of PDL1-NP-FEXO was 154.6 nm. Similar to free PD-L1 aptamer, PDL1-NP could also bind with PD-L1-expressing tumor cells (MDA-MB-231). Of note, compared with free PD-L1 aptamer, PDL1-NP significantly boosted tumor inhibition in CT26-bearing mice. Moreover, PDL1-NP-FEXO further enhanced the antitumor efficacy vs. PDL1-NP in an animal model, without raising systemic toxicity. These results indicate that PDL1-NP-FEXO represents a promising strategy to improve ICB efficacy and may have application potential in cancer immunotherapy.

Chitosan-coated bovine serum albumin nanoparticles for topical tetrandrine delivery in glaucoma: in vitro and in vivo assessment

Glaucoma is one of the leading causes of blindness. Therapies available suffer from several drawbacks including low bioavailability, repeated administration and poor patient compliance with adverse effects thereafter. In this study, bovine serum albumin nanoparticles (BSA-NPs) coated with chitosan(CS) were developed for the topical delivery of tetrandrine (TET) for glaucoma management. Optimized nanoparticles were prepared by desolvation. pH, BSA, CS and cross-linking agent concentrations effects on BSA-NPs colloidal properties were investigated. CS-BSA-NPs with particle size 237.9 nm and zeta potential 24 mV was selected for further evaluation. EE% exceeded 95% with sustained release profile. In vitro mucoadhesion was evaluated based on changes in viscosity and zeta potential upon incubation with mucin. Ex vivo transcorneal permeation was significantly enhanced for CS coated formulation. In vitro cell culture studies on corneal stromal fibroblasts revealed NPs biocompatibility with enhanced cellular uptake and improved antioxidant and anti-proliferative properties for the CS-coated formulation. Moreover, BSA-NPs were nonirritant as shown by HET-CAM test. Also, bioavailability in rabbit aqueous humor showed 2-fold increase for CS-TET-BSA-NPs compared to TET with a sustained reduction in intraocular pressure in a rabbit glaucoma model. Overall, results suggest CS-BSA-NPs as a promising platform for topical ocular TET delivery in the management of glaucoma.

Permeation of albumin through the skin depending on its concentration and the substrate used in simulated conditions in vivo

OBJECTIVE

Many drugs applied to the skin with a systemic effect do not have a therapeutic effect, due to the barrier posed by the complex structure of the skin. To counteract this, absorption promoters are often added to the drug formulation. The use of albumin as an effective drug carrier is increasingly being addressed. Albumin, a natural, non-toxic polymer, can target drugs to specific cells and extend their biological half-life. This study was designed to trace the permeation of albumin after topical administration to the skin as a potential carrier of therapeutic substances.

MATERIALS AND METHODS

Four dermal formulations based on different polymers were prepared: methyl cellulose, sodium alginate, hypromellose and chitosan with methyl cellulose, obtaining final concentrations of albumin of 2%, 1.5% and 1%. The permeation of albumin through the skin was examined under simulated in vivo conditions.

RESULTS

Most albumin permeated from the methylcellulose-based hydrogel. Depending on the concentration of albumin, permeation profiles were plotted and permeation rate constant and AUC_(0-24 h) were calculated.

CONCLUSION

Methylcellulose was the optimal polymer for albumin release, whereas hypromellose was the least favorable. The concentration of albumin influences the amount and rate of permeation of this protein. The optimal concentration was 10 mg/g, from which the most albumin penetrated and the fastest. Human skin appeared to be more permeable to albumin than pig skin. However, the similar permeation profile through both membranes successfully allows the use of pig skin to track and evaluate the permeation of therapeutic substances with systemic effects.

Protein scaffolds in human clinics

Fundamental clinical areas such as drug delivery and regenerative medicine require biocompatible materials as mechanically stable scaffolds or as nanoscale drug carriers. Among the wide set of emerging biomaterials, polypeptides offer enticing properties over alternative polymers, including full biocompatibility, biodegradability, precise interactivity, structural stability and conformational and functional versatility, all of them tunable by conventional protein engineering. However, proteins from non-human sources elicit immunotoxicities that might bottleneck further development and narrow their clinical applicability. In this context, selecting human proteins or developing humanized protein versions as building blocks is a strict demand to design non-immunogenic protein materials. We review here the expanding catalogue of human or humanized proteins tailored to execute different levels of scaffolding functions and how they can be engineered as self-assembling materials in form of oligomers, polymers or complex networks. In particular, we emphasize those that are under clinical development, revising their fields of applicability and how they have been adapted to offer, apart from mere mechanical support, highly refined functions and precise molecular interactions.

Facile Fabrication of Transparent and Opaque Albumin Methacryloyl Gels with Highly Improved Mechanical Properties and Controlled Pore Structures

For porous protein scaffolds to be employed in tissue-engineered structures, the development of cost-effective, macroporous, and mechanically improved protein-based hydrogels, without compromising the original properties of native protein, is crucial. Here, we introduced a facile method of albumin methacryloyl transparent hydrogels and opaque cryogels with adjustable porosity and improved mechanical characteristics via controlling polymerization temperatures (room temperature and −80 °C). The structural, morphological, mechanical, and physical characteristics of both porous albumin methacryloyl biomaterials were investigated using FTIR, CD, SEM, XRD, compression tests, TGA, and swelling behavior. The biodegradation and biocompatibility of the various gels were also carefully examined. Albumin methacryloyl opaque cryogels outperformed their counterpart transparent hydrogels in terms of mechanical characteristics and interconnecting macropores. Both materials demonstrated high mineralization potential as well as good cell compatibility. The solvation and phase separation owing to ice crystal formation during polymerization are attributed to the transparency of hydrogels and opacity of cryogels, respectively, suggesting that two fully protein-based hydrogels could be used as visible detectors/sensors in medical devices or bone regeneration scaffolds in the future.

Fluorescent Nanosystems for Drug Tracking and Theranostics: Recent Applications in the Ocular Field

The greatest challenge associated with topical drug delivery for the treatment of diseases affecting the posterior segment of the eye is to overcome the poor bioavailability of the carried molecules. Nanomedicine offers the possibility to overcome obstacles related to physiological mechanisms and ocular barriers by exploiting different ocular routes. Functionalization of nanosystems by fluorescent probes could be a useful strategy to understand the pathway taken by nanocarriers into the ocular globe and to improve the desired targeting accuracy. The application of fluorescence to decorate nanocarrier surfaces or the encapsulation of fluorophore molecules makes the nanosystems a light probe useful in the landscape of diagnostics and theranostics. In this review, a state of the art on ocular routes of administration is reported, with a focus on pathways undertaken after topical application. Numerous studies are reported in the first section, confirming that the use of fluorescent within nanoparticles is already spread for tracking and biodistribution studies. The first section presents fluorescent molecules used for tracking nanosystems’ cellular internalization and permeation of ocular tissues; discussions on the classification of nanosystems according to their nature (lipid-based, polymer-based, metallic-based and protein-based) follows. The following sections are dedicated to diagnostic and theranostic uses, respectively, which represent an innovation in the ocular field obtained by combining dual goals in a single administration system. For its great potential, this application of fluorescent nanoparticles would experience a great development in the near future. Finally, a brief overview is dedicated to the use of fluorescent markers in clinical trials and the market in the ocular field.

Formulation and Characterization Studies of Inclusion Complexes of Voriconazole for Possible Ocular Application

In our study Voriconazole (VOR) was selected as an active agent to be used for the treatment of ocular fungal infections. To overcome low aqueous solubility of VOR, inclusion complexes with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-cyclodextrin (HP-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) hydroxypropyl-γ-cyclodextrin (HP-γ-CD), methyl-β-cyclodextrin (M-β-CD) and sulfabutylether-β-cyclodextrin (SBE-β-CD) were formulated. Characterization studies revealed that inclusion complexes were formulated successfully with lyophilization method. Aqueous solubility of VOR was enhanced up to 86 fold with the formation of the inclusion complexes. MTT analyses results revealed the safety of the complexes on 3T3 mouse fibroblast cell lines while Microbroth Dilution Method revealed the remarkable antifungal activities of the complexes. Analyses results revealed that inclusion complexes will overcome the poor ocular bioavailability of VOR resulting in efficient treatment of severe ocular fungal infections.

Development of mucoadhesive thiomeric chitosan nanoparticles for the targeted ocular delivery of vancomycin against Staphylococcus aureus resistant strains

This study aims to formulate mucoadhesive vancomycin loaded thiolated chitosan (TCS) nanoparticles. These nanoparticles are mucoadhesive and enhance the retention of the drug at the ocular site. For this purpose, TCS loaded vancomycin nanoparticles were prepared by the ion-gelation method and were characterized for their size, shape, polydispersity index, mucoadhesion, cellular uptake and anti-inflammatory activity. The average size of the synthesized nanoparticles was found to be 288 nm with positive zeta potential. Moreover, 85% vancomycin was successfully encapsulated in TCS nanoparticles by using this method. A 2-fold increase in mucoadhesion was found as compared to non-thiolated vancomycin formulation (p < 0.05). Zone of inhibition of vancomycin loaded TCS was also significantly improved compared to non-thiolated chitosan nanoparticles and vancomycin alone. In-vivo anti-inflammatory evaluation via histopathology resulted in ocular healing. Based on the results, it is inferred that TCS nanoparticles are a promising drug delivery carrier system for ocular delivery of vancomycin.

Polymer-Based Nanosystems-A Versatile Delivery Approach

Polymer-based nanoparticles of tailored size, morphology, and surface properties have attracted increasing attention as carriers for drugs, biomolecules, and genes. By protecting the payload from degradation and maintaining sustained and controlled release of the drug, polymeric nanoparticles can reduce drug clearance, increase their cargo's stability and solubility, prolong its half-life, and ensure optimal concentration at the target site. The inherent immunomodulatory properties of specific polymer nanoparticles, coupled with their drug encapsulation ability, have raised particular interest in vaccine delivery. This paper aims to review current and emerging drug delivery applications of both branched and linear, natural, and synthetic polymer nanostructures, focusing on their role in vaccine development.