Development of a novel hyaluronic acid membrane for the treatment of ocular surface diseases

Biogenic Amino Acid Cross-Linked Hyaluronic Acid Nanoparticles Containing Dexamethasone for the Treatment of Dry Eye Syndrome

Ocular barriers, poor retention time, and frequent ocular discharge suppress the activity of Dexamethasone. Arginine (Arg) and hyaluronic acid (HA) are crucial for maintaining ocular health because of their unique biological benefits. In this study, we investigated the cationic properties of arginine to develop dexamethasone-loaded HA nanoparticles (ADHA NPs) and evaluated their therapeutic potential in alleviating dry eye syndrome using various reported in-vitro and in-vivo techniques. The ionic cross-linking method was used to prepare ADHA NPs. The ADHA NPs exhibited nearly 94.99 ± 4.16% drug release at the end of 6 h and followed the Korsemeyar-Peppas kinetic model (R2 = 0.9811). Moreover, the developed formulation exhibited a higher water retention capacity, i.e., 86.89 ± 1.41%, and revealed enhanced mucoadhesion characteristics. ADHA NPs also exhibited significant anti-inflammatory effects (p < 0.001) compared to dexamethasone in LPS-induced RAW 264.7 cell lines against proinflammatory cytokines IL-1 β, NO and TNF-α. Furthermore, cell line studies in HCECs (human corneal epithelial cells) showed cytocompatibility and a dose-dependent uptake of ADHA NPs. ADHA NPs also maintained the cell integrity against 0.005% benzalkonium chloride (BAC) induced dry eye model on HCECs. Further, the Schirmer tear test showed twofold enhanced tear production in the developed formulation, and ADHA NPs seem to maintain the uniform structure of the tear. In vivo, drug retention studies ensured the good retention properties of ADHA NPs up to 12 h. In conclusion, ADHA NPs, because of their anti-inflammatory, mucoadhesiveness, modified drug release capacity, and higher drug retention properties, could serve as a potential therapeutic alternative for treating dry eye conditions.

Bio-orthogonal crosslinking and hyaluronan facilitate transparent healing after treatment of deep corneal injuries with in situ-forming hydrogels

Corneal transplantation is the primary treatment for corneal blindness, affecting millions globally. However, challenges like donor scarcity and surgical complications remain. Recently, in situ-forming corneal stroma substitutes have emerged, offering potential solutions to these limitations. These substitutes enable liquid-to-hydrogel formation in situ, eliminating sutures and reducing complications. Here we performed a direct, side-by-side comparison of a composite hyaluronan-collagen (HA-Col) hydrogel crosslinked by either photochemistry or bio-orthogonal chemistry to ascertain the impact of reaction specificity on corneal wound healing. Testing in rodent and rabbit models suggests that composite HA-Col gels crosslinked by bio-orthogonal chemistry results in more rapid and optically favorable wound healing compared to the same composition crosslinked by photochemistry as well as bio-orthogonally crosslinked collagen alone. These findings underscore biochemical parameters that may be important to the success of crosslinked, in situ-forming hydrogels as an alternative to corneal transplantation, with the potential for expanded access to treatment and improved outcomes.

How to Fabricate Hyaluronic Acid for Ocular Drug Delivery

This review aims to examine existing research on the development of ocular drug delivery devices utilizing hyaluronic acid (HA). Renowned for its exceptional biocompatibility, viscoelastic properties, and ability to enhance drug bioavailability, HA is a naturally occurring biopolymer. The review discussed specific mechanisms by which HA enhances drug delivery, including prolonging drug residence time on ocular surfaces, facilitating controlled drug release, and improving drug penetration through ocular tissues. By focusing on these unique functionalities, this review highlights the potential of HA-based systems to revolutionize ocular treatment. Various fabrication techniques for HA-based ocular drug delivery systems, including hydrogels, nanoparticles, and microneedles, are discussed, highlighting their respective advantages and limitations. Additionally, this review explores the clinical applications of HA-based devices in treating a range of ocular diseases, such as dry eye syndrome, glaucoma, retinal disorders, and ocular infections. By comparing the efficacy and safety profiles of these devices with traditional ocular drug delivery methods, this review aims to provide a comprehensive understanding of the potential benefits and challenges associated with HA-based systems. Moreover, this review discusses current limitations and future directions in the field, such as the need for standardized fabrication protocols, long-term biocompatibility studies, and large-scale clinical trials. The insights and advancements presented in this review aim to guide future research and development efforts, ultimately enhancing the effectiveness of ocular drug delivery and improving patient outcomes.

Are We Overlooking Harms of BDDE-Cross-Linked Dermal Fillers? A Scoping Review

1,4-Butanediol ether (BDDE) is widely used as a cross-linker for hyaluronic acid in dermal fillers. The purpose of this scoping review was to determine the state of knowledge about the behaviour of cross-linked substances and safety of BDDE application. The rationale behind the review came from the clinical experience of one of the authors (KS), who noticed adverse reactions after BDDE-linked hyaluronan application. The scoping review was conducted according to PRISMA-ScR guidelines. Out of 399 articles, 52 met the inclusion criteria. Data on study design, sample/population, aims, methodology, outcomes and funding were extracted. Results were charted according to 6 subtopics: rheological properties, hydrogel stability, BDDE toxicity, immunogenicity, tissue interactions and clinical studies. In vitro, cross-linked hydrogels were characterized as effective fillers in terms of viscosity and elasticity; however, previously uncharacterized by-products of the cross-linking reaction were found. Most in vivo studies reported increased dermis regeneration, vascularization and anti-inflammatory cytokine release after implantation of BDDE-cross-linked substances. In clinical studies, BDDE was shown to sensitize subjects to 1,6-hexanediol ether and other substances found in epoxy resin systems. Occupational dermatitis and hypersensitivity reactions were documented. Our review shows that BDDE may have long-term adverse effects, which are overlooked in the safety assessment of fillers. Reviews on BDDE conducted so far have mostly been sponsored by the industry, potentially leading to incomplete reporting of adverse effects. A review of the occurrence of allergic reactions after commercial dermal filler use and analysis of possibly harmful by-products of BDDE hyaluronan degradation are needed.Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Novel ophthalmic hyaluronic acid-hydrogel with curcumin nanoparticles for enhanced healing of ulcerative keratitis in rabbit model

Corneal ulcers, whether melting or indolent, are common in humans and companion animals. Treatment involves local administration of antibiotic eye drops and corneal healing drugs. Compared to traditional treatments for ulcerative keratitis, herbal medicines offer unique advantages, such as potent anti-inflammatory effects and inhibition of proinflammatory cytokines. Curcumin, extracted from the Curcuma Longa plant, possesses extensive pharmacological properties, such as anti-inflammatory, anti-cancer, and antioxidant properties, and is used in various medicines. In this study, we developed a novel ophthalmic drop hydrogel using a formulation of Curcumin NPs encapsulated with β-cyclodextrin and hyaluronic acid, to accelerate corneal healing and improve the quality of healed structures. The formation of Curcumin NPs into Hyaluronic acid-based hydrogels was characterized by zeta, FTIR, and scanning electron microscope (SEM) analyses. A total of 25 healthy male New Zealand Albino rabbits were experimentally induced with ulcerative keratitis and treated individually with topical medication. Rabbits were divided into five groups. Fluorescein dye staining, corneal clarity score, Schirmer tear test, proinflammatory cytokine measurement, and pathologic factors assessments were used to evaluate the optimised Curcumin NPs with β-cyclodextrin in Hyaluronic acid hydrogel. Our results demonstrated that the optimized Curcumin NPs with β-cyclodextrin in hyaluronic acid hydrogel significantly reduced the frequency of medication administration compared to conventional therapies, enhancing the quality of healed structures and effectively treating ulcerative keratitis. All findings in this study provide new insight into designing and fabricating novel ophthalmic medicine for ulcerative keratitis for topical usage.

Kuragel: A biomimetic hydrogel scaffold designed to promote corneal regeneration

Cornea-related injuries are the most common cause of blindness worldwide. Transplantation remains the primary approach for addressing corneal blindness, though the demand for donor corneas outmatches the supply by millions. Tissue adhesives employed to seal corneal wounds have shown inefficient healing and incomplete vision restoration. We have developed a biodegradable hydrogel - Kuragel, with the ability to promote corneal regeneration. Functionalized gelatin and hyaluronic acid form photo-crosslinkable hydrogel with transparency and compressive modulus similar to healthy human cornea. Kuragel composition was tuned to achieve sufficient adhesive strength for sutureless integration to host tissue, with minimal swelling post-administration. Studies in the New Zealand rabbit mechanical injury model affecting corneal epithelium and stroma demonstrate that Kuragel efficiently promotes re-epithelialization within 1 month of administration, while stroma and sub-basal nerve plexus regenerate within 3 months. We propose Kuragel as a regenerative treatment for patients suffering from corneal defects including thinning, by restoration of transparency and thickness.

Effect of a New Hyaluronic Acid Hydrogel Dermal Filler Cross-Linked With Lysine Amino Acid for Skin Augmentation and Rejuvenation

BACKGROUND

Hyaluronic acid (HA) fillers are the most popular filler agents for skin rejuvenation. Although 1,4-butanediol diglycidyl ether is regarded as a relatively safe cross-linker, it still exhibits certain cytotoxicity.

OBJECTIVES

We presented here an amino acid-cross-linked HA (ACHA) which was obtained by an amidation reaction with lysine and HA. This study aimed to investigate ACHA's efficacy and safety for skin augmentation and rejuvenation.

METHODS

Rheology, compressive tests, and swelling experiments were conducted to investigate ACHA's mechanical and viscoelastic properties. The effects of ACHA on the human keratinocytes (HaCaT) cells and the human dermal fibroblast (HDF) were investigated by Transwell and wound healing assays. Its impacts on the epithelial thickness and collagen synthesis were further examined in a mouse experimental model. We recruited 50 patients with moderate to severe nasolabial folds (NLFs). The patients were randomly allocated to receive ACHA or Restylane injections. The resulting retention rates of HA and the Wrinkle Severity Rating Scale and Global Aesthetic Improvement Scale outcomes were evaluated and compared.

RESULTS

ACHA exhibited good viscoelasticity. It not only promoted migration and proliferation of HaCat and HDF and secretion of various growth factors but also increased skin thickness and promoted the generation of collagen. Patients who received ACHA had more residual volume 12 months after treatment. ACHA exhibited a promising augmentation effect in NLF correction with few adverse reactions.

CONCLUSIONS

ACHA has shown promise as a biomaterial with excellent biocompatibility and viscoelastic characteristics in both research and the clinic.See the abstract translated into Hindi, Portuguese, Korean, German, Italian, Arabic, Chinese, and Taiwanese online here: https://doi.org/10.1093/asj/sjad169.

LEVEL OF EVIDENCE: 2

Carbohydrate polymer-based bioadhesive formulations and their potentials for the treatment of ocular diseases: A review

Eyes are directly exposed to the outer environment and susceptible to infections, leading to various ocular disorders. Local medication is preferred to treat eye diseases due to its convenience and compliance. However, the rapid clearance of the local formulations highly limits the therapeutic efficacy. In the past decades, several carbohydrate bioadhesive polymers (CBPs), such as chitosan and hyaluronic acid, have been used in ophthalmology for sustained ocular drug delivery. These CBP-based delivery systems have improved the treatment of ocular diseases to a large extent but also caused some undesired effects. Herein, we aim to summarize the applications of some typical CBPs (including chitosan, hyaluronic acid, cellulose, cyclodextrin, alginate and pectin) in treating ocular diseases from the general view of ocular physiology, pathophysiology and drug delivery, and to provide a comprehensive understanding of the design of the CBP-based formulations for ocular use. The patents and clinical trials of CBPs for ocular management are also discussed. In addition, a discussion on the concerns of CBPs in clinical use and the possible solutions is presented.

A LC-QTOF Method for the Determination of PEGDE Residues in Dermal Fillers

Hyaluronic acid is one of the most important ingredients in dermal fillers, where it is often cross-linked to gain more favorable rheological properties and to improve the implant duration. Poly(ethylene glycol) diglycidyl ether (PEGDE) has been recently introduced as a crosslinker because of its very similar chemical reactivity with the most-used crosslinker BDDE, while giving special rheological properties. Monitoring the amount of the crosslinker residues in the final device is always necessary, but in the case of PEGDE, no methods are available in literature. Here, we present an HPLC-QTOF method, validated according to the guidelines of the International Council on Harmonization, which enables the efficient routine examination of the PEGDE content in HA hydrogels.

Hyaluronic acid - PVA films for the simultaneous delivery of dexamethasone and levofloxacin to ocular tissues

Ocular drug delivery is challenging due to the poor drug penetration across ocular barriers and short retention time of the formulation at the application site. Films, applied as inserts or implants, can be used to increase residence time while controlling drug release. In this work, hydrophilic films made of hyaluronic acid and two kinds of PVA were loaded with dexamethasone (included as hydroxypropylcyclodextrin complex) and levofloxacin. This association represents one of the main treatments for the post cataract surgery management, and it is also promising for eye infections whith pain and inflammation. Films were characterized in terms of swelling and drug release and were then applied to porcine eye bulbs and isolated ocular tissues. Film swelling leads to the formation of either a gel (3D swelling) or a larger film (2D swelling) depending on the type of PVA used. Films, prepared in an easy and scalable method, demonstrated high loading capacity, controlled drug release and the capability to deliver dexamethasone and levofloxacin to the cornea and across the sclera, to potentially target also the posterior eye segment. Overall, this device can be considered a multipurpose delivery platform intended for the concomitant release of lipophilic and hydrophilic drugs.

In Situ-Forming Collagen-Hyaluronate Semi-Interpenetrating Network Hydrogel Enhances Corneal Defect Repair

Purpose

Millions worldwide suffer vision impairment or blindness from corneal injury, and there remains an urgent need for a more effective and accessible way to treat corneal defects. We have designed and characterized an in situ-forming semi-interpenetrating polymer network (SIPN) hydrogel using biomaterials widely used in ophthalmology and medicine.

Methods

The SIPN was formed by cross-linking collagen type I with bifunctional polyethylene glycol using N-hydroxysuccinimide ester chemistry in the presence of linear hyaluronic acid (HA). Gelation time and the mechanical, optical, swelling, and degradation properties of the SIPN were assessed. Cytocompatibility with human corneal epithelial cells and corneal stromal stem cells (CSSCs) was determined in vitro, as was the spatial distribution of encapsulated CSSCs within the SIPN. In vivo wound healing was evaluated by multimodal imaging in an anterior lamellar keratectomy injury model in rabbits, followed by immunohistochemical analysis of treated and untreated tissues.

Results

The collagen-hyaluronate SIPN formed in situ without an external energy source and demonstrated mechanical and optical properties similar to the cornea. It was biocompatible with human corneal cells, enhancing CSSC viability when compared with collagen gel controls and preventing encapsulated CSSC sedimentation. In vivo application of the SIPN significantly reduced stromal defect size compared with controls after 7 days and promoted multilayered epithelial regeneration.

Conclusions

This in situ-forming SIPN hydrogel may be a promising alternative to keratoplasty and represents a step toward expanding treatment options for patients suffering from corneal injury.

Translational Relevance

We detail the synthesis and initial characterization of an SIPN hydrogel as a potential alternative to lamellar keratoplasty and a tunable platform for further development in corneal tissue engineering and therapeutic cell delivery.

Ciprofloxacin-Loaded Zein/Hyaluronic Acid Nanoparticles for Ocular Mucosa Delivery

Bacterial conjunctivitis is a worldwide problem that, if untreated, can lead to severe complications, such as visual impairment and blindness. Topical administration of ciprofloxacin is one of the most common treatments for this infection; however, topical therapeutic delivery to the eye is quite challenging. To tackle this, nanomedicine presents several advantages compared to conventional ophthalmic dosage forms. Herein, the flash nanoprecipitation technique was applied to produce zein and hyaluronic acid nanoparticles loaded with ciprofloxacin (ZeinCPX_HA NPs). ZeinCPX_HA NPs exhibited a hydrodynamic diameter of <200 nm and polydispersity index of <0.3, suitable for ocular drug delivery. In addition, the freeze-drying of the nanoparticles was achieved by using mannitol as a cryoprotectant, allowing their resuspension in water without modifying the physicochemical properties. Moreover, the biocompatibility of nanoparticles was confirmed by in vitro assays. Furthermore, a high encapsulation efficiency was achieved, and a release profile with an initial burst was followed by a prolonged release of ciprofloxacin up to 24 h. Overall, the obtained results suggest ZeinCPX_HA NPs as an alternative to the common topical dosage forms available on the market to treat conjunctivitis.

Hyaluronic Acid: Its Versatile Use in Ocular Drug Delivery with a Specific Focus on Hyaluronic Acid-Based Polyelectrolyte Complexes

Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) that are capable of surpassing the limitations associated with conventional intraocular anterior and posterior segment treatments. Nanoformulations, including those synthesised from the natural, hydrophilic glycosaminoglycan, hyaluronic acid (HA), have gained significant traction due to their enhanced intraocular permeation, longer retention times, high physiological stability, inherent biocompatibility, and biodegradability. However, conventional nanoformulation preparation methods often require large volumes of organic solvent, chemical cross-linkers, and surfactants, which can pose significant toxicity risks. We present a comprehensive, critical review of the use of HA in the field of ophthalmology and ocular drug delivery, with a discussion of the physicochemical and biological properties of HA that render it a suitable excipient for drug delivery to both the anterior and posterior segments of the eye. The pivotal focus of this review is a discussion of the formation of HA-based nanoparticles via polyelectrolyte complexation, a mild method of preparation driven primarily by electrostatic interaction between opposing polyelectrolytes. To the best of our knowledge, despite the growing number of publications centred around the development of HA-based polyelectrolyte complexes (HA-PECs) for ocular drug delivery, no review articles have been published in this area. This review aims to bridge the identified gap in the literature by (1) reviewing recent advances in the area of HA-PECs for anterior and posterior ODD, (2) describing the mechanism and thermodynamics of polyelectrolyte complexation, and (3) critically evaluating the intrinsic and extrinsic formulation parameters that must be considered when designing HA-PECs for ocular application.

A Randomized Controlled Trial to Manage Postoperative Ocular Pain after Pterygium Excision with Conjunctival Autograft Transplantation with a Single Application of 2% Sodium Hyaluronate

Purpose

To assess the effectiveness of a single application of 2% sodium hyaluronate (SH) in controlling pain after pterygium excision as compared with that of a control group.

Methods

We performed a prospective randomized controlled trial in the patients who underwent pterygium excision. The outcome of topical application of 2.0% SH was measured using the visual analogue scale (VAS), in comparison with that observed in a control group (without SH). The area of ocular surface defects was assessed by ImageJ freeware. Analysis of pain scores and ocular surface defects were observed from both groups immediately after the operation, Day 0, and 3 subsequent days.

Results

Thirty patients were randomly divided into control group and SH treatment group. The initial area of the ocular surface defect on Day 0 was approximately the same for both groups (p=0.242). The medians of pain score assessed by the VAS on Days 0, 1, and 2 were 5, 3, and 0 for the SH group and 6, 5, and 3 for the control group, respectively. The pain score was statistically significantly decreased in the SH group compared to the control group on Day 1 (p < 0.001) and Day 2 (p < 0.001). The pain level of both groups was nearly the same on Day 3 (p=0.141). The area of ocular surface defects was significantly different between two groups on Day 1 (p < 0.001) and Day 2 (p < 0.001). Postoperative complications were not observed.

Conclusion

A single topical application of 2% SH in pterygium excision was effective in relieving pain in the early postoperative period without any adverse effects. This innovation may provide alternative pain control in pterygium surgery.

Moxifloxacin releasing intraocular implant based on a cross-linked hyaluronic acid membrane

Intraocular antibiotic delivery is an important technique to prevent bacterial infection after ophthalmic surgery, such as cataract surgery. Conventional drug delivery methods, such as antibiotic eye drops, have limitations for intraocular drug delivery due to the intrinsic barrier effect of the cornea. Therefore, frequent instillation of antibiotic eyedrops is necessary to reach a sufficient bactericidal concentration inside the eye. In this study, an intraocular implant, MXF-HA, that combines hyaluronic acid (HA) and moxifloxacin (MXF) was developed to increase the efficiency of intraocular drug delivery after surgery. MXF-HA is manufactured as a thin, transparent, yellow-tinted membrane. When inserted into the eye in a dry state, MXF-HA is naturally hydrated and settles in the eye, and the MXF contained therein is delivered by hydrolysis of the polymer over time. It was confirmed through in vivo experiments that MXF delivery was maintained in the anterior chamber of the eye at a concentration sufficient to inhibit Pseudomonas aeruginosa and Staphylococcus aureus for more than 5 days after implantation. These results suggest that MXF-HA can be utilized as a potential drug delivery method for the prevention and treatment of bacterial infections after ophthalmic surgery.

Preparation of Liposomal Formulations for Ocular Delivery of Thymoquinone: In Vitro Evaluation in HCEC-2 e HConEC Cells

Thymoquinone (TQ) is the main constituent of Nigella sativa L. essential oil. In vitro studies have shown its protective effect against H₂O₂-induced oxidative stress in human retinal pigment epithelium cells, and in vivo experiments have demonstrated its effect in decreasing corneal neovascularization and reducing the inflammation in an experimental dry eye model in mice. Its therapeutic use is limited by poor bioavailability, low solubility, and scarce permeability. In this study, two liposomal formulations have been developed, both of which consist of phosphatidylcholine and Plurol Oleique, a liquid lipid, and one of which is coated with 0.1% w/v hyaluronic acid (HA) to increase both TQ solubility and its ocular therapeutic potential. Each formulation has a size <200 nm and an EE% around 70%, determined by scattering techniques and the HPLC-DAD analytical method, respectively, and they result in a 2-fold increase in TQ solubility. HA-coated liposomes are stable over 2 months at +4 °C, and coated and uncoated liposomes present a gradual and prolonged release of TQ. Two cell lines, human corneal epithelial cells (HCEC-2) and human conjunctival epithelial cells (HConEC) were used to investigate the safety of the liposomal formulations. Uptake studies were also performed using fluorescent liposomes. Both liposomes and, in particular, HA-coated liposomes reduce the TQ toxicity observed at high doses in both HCEC-2 and HConEC cells, and both formulations increase the absorption at the cellular level and especially at the nucleus level, with a more pronounced effect for HA-coated liposomes.

Effect of 2% Hyaluronic Acid on the Rate of Healing of Corneal Epithelial Defect After Pterygium Surgery: A Randomized Controlled Trial

Purpose

The study aimed to investigate the effects of 2% hyaluronic acid (HA) on corneal epithelial defect after pterygium surgery in comparison with the control group, measured in terms of the healing rate of corneal epithelial defect and pain score after surgery.

Methods

In this double-blind randomized clinical trial, fifty patients with primary pterygium were randomized into 2 groups: a control group or the group treated with a single topical application of 2% HA. Comprehensive ophthalmological examinations included measuring the area of corneal epithelium defect using ImageJ freeware and the pain score assessment after the operation.

Results

The mean and SD of the area of epithelial defect measured on postoperative Day 0, 1, and 2 were 10.89 ± 1.33 mm², 5.04 ± 0.87mm², and 2.44 ± 0.74 mm² for the HA group, and 11.14 ± 1.11 mm², 7.74 ± 1.17 mm², and 5.31 ± 1.15 mm² for the control group, respectively. While the initial area of the defect on Day 0 was essentially the same for both groups (p = 0.478), the area of the defect in the HA group was significantly smaller on both Day 1 and Day 2 (p < 0.001, p < 0.001), respectively. Similarly, the HA group exhibited a statistically significant higher rate of healing for the cornea epithelial defect over Day 0 and 1 compared to the control group (5.85 ± 0.89 mm²/day vs 3.14 ± 1.28 mm²/day, p < 0.001), respectively. The median (range) pain scores were evaluated at Day 0 was 7 (4–10) in the HA group and 7 (3–10) in the control group (p = 0.953). There was no statistically significant difference between two groups (p > 0.05) for Days 1, 2, and 3.

Conclusion

A single topical application of 2% HA tended to accelerate the healing process of corneal epithelium defect after pterygium surgery without any observable adverse effects during short-term follow-up.

Development of Lactoferrin-Loaded Liposomes for the Management of Dry Eye Disease and Ocular Inflammation

Dry eye disease (DED) is a high prevalent multifactorial disease characterized by a lack of homeostasis of the tear film which causes ocular surface inflammation, soreness, and visual disturbance. Conventional ophthalmic treatments present limitations such as low bioavailability and side effects. Lactoferrin (LF) constitutes a promising therapeutic tool, but its poor aqueous stability and high nasolacrimal duct drainage hinder its potential efficacy. In this study, we incorporate lactoferrin into hyaluronic acid coated liposomes by the lipid film method, followed by high pressure homogenization. Pharmacokinetic and pharmacodynamic profiles were evaluated in vitro and ex vivo. Cytotoxicity and ocular tolerance were assayed both in vitro and in vivo using New Zealand rabbits, as well as dry eye and anti-inflammatory treatments. LF loaded liposomes showed an average size of 90 nm, monomodal population, positive surface charge and a high molecular weight protein encapsulation of 53%. Biopharmaceutical behaviour was enhanced by the nanocarrier, and any cytotoxic effect was studied in human corneal epithelial cells. Developed liposomes revealed the ability to reverse dry eye symptoms and possess anti-inflammatory efficacy, without inducing ocular irritation. Hence, lactoferrin loaded liposomes could offer an innovative nanotechnological tool as suitable approach in the treatment of DED.

Natural Polymeric Scaffolds for Tissue Engineering Applications

Natural polymeric scaffolds can be used for tissue engineering applications such as cell delivery and cell-free supporting of native tissues. This is because of their desirable properties such as; high biocompatibility, tunable mechanical strength and conductivity, large surface area, porous- and extracellular matrix (ECM)-mimicked structures. Specifically, their less toxicity and biocompatibility makes them suitable for several tissue engineering applications. For these reasons, several biopolymeric scaffolds are currently being explored for numerous tissue engineering applications. To date, research on the nature, chemistry, and properties of nanocomposite biopolymers are been reported, while the need for a comprehensive research note on more tissue engineering application of these biopolymers remains. As a result, this present study comprehensively reviews the development of common natural biopolymers as scaffolds for tissue engineering applications such as cartilage tissue engineering, cornea repairs, osteochondral defect repairs, and nerve regeneration. More so, the implications of research findings for further studies are presented, while the impact of research advances on future research and other specific recommendations are added as well.