Monoclonal Antibodies for the Treatment of Ocular Diseases.

Monoclonal antibodies (mAbs) have revolutionized the landscape of cancer therapy, offering unprecedented specificity and diverse mechanisms to combat malignant cells. These biologic agents have emerged as a cornerstone in targeted cancer treatment, binding to specific antigens on cancer cells and exerting their therapeutic effects through various mechanisms, including inhibition of signaling pathways, antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-dependent cellular phagocytosis (ADCP). The unique ability of mAbs to engage the immune system and directly interfere with cancer cell function has significantly enhanced the therapeutic armamentarium against a broad spectrum of malignancies. mAbs were initially studied in oncology; however, today, treatments have been developed for eye diseases. This review discusses the current applications of mAbs for the treatment of ocular diseases, discussing the specificity and the variety of mechanisms by which these molecules exhibit their therapeutic effects. The benefits, drawbacks, effectiveness, and risks associated with using mAbs in ophthalmology are highlighted, focusing on the most relevant ocular diseases and mAbs currently in use. Technological advances have led to in vitro production methods and recombinant engineering techniques, allowing the development of chimeric, humanized, and fully human mAbs. Nowadays, many humanized mAbs have several applications, e.g., for the treatment of age-related macular disease, diabetic retinopathy, and uveitis, while studies about new applications of mAbs, such as for SARS-CoV-2 infection, are also currently ongoing to seek more efficient and safe approaches to treat this new ocular disease.

Phytocannabinoids: Chromatographic Screening of Cannabinoids and Loading into Lipid Nanoparticles.

Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC) are receiving increasing interest as an approach to encapsulate natural extracts to increase the physicochemical stability of bioactives. Cannabis extract-derived cannabidiol (CBD) has potent therapeutic properties, including anti-inflammatory, antioxidant, and neuroprotective properties. In this work, physicochemical characterization was carried out after producing Compritol-based nanoparticles (cSLN or cNLC) loaded with CBD. Then, the determination of the encapsulation efficiency (EE), loading capacity (LC), particle size (Z-Ave), polydispersity index (PDI), and zeta potential were performed. Additionally, the viscoelastic profiles and differential scanning calorimetry (DSC) patterns were recorded. As a result, CBD-loaded SLN showed a mean particle size of 217.2 ± 6.5 nm, PDI of 0.273 ± 0.023, and EE of about 74%, while CBD-loaded NLC showed Z-Ave of 158.3 ± 6.6 nm, PDI of 0.325 ± 0.016, and EE of about 70%. The rheological analysis showed that the loss modulus for both lipid nanoparticle formulations was higher than the storage modulus over the applied frequency range of 10 Hz, demonstrating that they are more elastic than viscous. The crystallinity profiles of both CBD-cSLN (90.41%) and CBD-cNLC (40.18%) were determined. It may justify the obtained encapsulation parameters while corroborating the liquid-like character demonstrated in the rheological analysis. Scanning electron microscopy (SEM) study confirmed the morphology and shape of the developed nanoparticles. The work has proven that the solid nature and morphology of cSLN/cNLC strengthen these particles' potential to modify the CBD delivery profile for several biomedical applications.

Therapeutic Approaches for Age-Related Macular Degeneration.

Damage to the retinal pigment epithelium, Bruch's membrane and/or tissues underlying macula is known to increase the risk of age-related macular degeneration (AMD). AMD is commonly categorized in two distinct types, namely, the nonexudative (dry form) and the exudative (wet form). Currently, there is no ideal treatment available for AMD. Recommended standard treatments are based on the use of vascular endothelial growth factor (VEGF), with the disadvantage of requiring repeated intravitreal injections which hinder patient's compliance to the therapy. In recent years, several synthetic and natural active compounds have been proposed as innovative therapeutic strategies against this disease. There is a growing interest in the development of formulations based on nanotechnology because of its important role in the management of posterior eye segment disorders, without the use of intravitreal injections, and furthermore, with the potential to prolong drug release and thus reduce adverse effects. In the same way, 3D bioprinting constitutes an alternative to regeneration therapies for the human retina to restore its functions. The application of 3D bioprinting may change the current and future perspectives of the treatment of patients with AMD, especially those who do not respond to conventional treatment. To monitor the progress of AMD treatment and disease, retinal images are used. In this work, we revised the recent challenges encountered in the treatment of different forms of AMD, innovative nanoformulations, 3D bioprinting, and techniques to monitor the progress.

Non-melanoma skin cancers: physio-pathology and role of lipid delivery systems in new chemotherapeutic treatments.

Non-melanoma carcinoma has high incidence rates and has two most common subtypes: basal cell carcinoma and squamous cell carcinoma. This type of carcinoma is usually not fatal; however, it can destroy sensory organs such as the nose, ears, and lips. The treatment of these injuries using non-invasive methods is thus strongly recommended. Some treatments for non-melanoma carcinoma are already well defined, such as surgery, cryosurgery, curettage and electrode section, and radiotherapy; however, these conventional treatments cause inflammation and scarring. In the non-surgical treatment of non-melanoma carcinoma, the topical administration of chemotherapeutic drugs contributes for an effective treatment with reduced side effects. However, the penetration of anticancer drugs in the deeper layers of the skin is required. Lipid delivery systems (liposomes, solid lipid nanoparticles, nanostructured lipid carriers) have been developed to overcome epidermal barrier of the skin and to allow the drugs to reach tumor cells. These lipid nanoparticles contribute to control the release profile of the loaded chemotherapeutic drugs, maintaining their stability and increasing death of tumor cells. In this review, the characteristics of non-melanoma carcinoma will be discussed, describing the main existing treatments, together with the contribution of lipid delivery systems as an innovative approach to increase the effectiveness of topical therapies for non-melanoma carcinomas.

Natural Ergot Alkaloids in Ocular Pharmacotherapy: Known Molecules for Novel Nanoparticle-Based Delivery Systems.

Several pharmacological properties are attributed to ergot alkaloids as a result of their antibacterial, antiproliferative, and antioxidant effects. Although known for their biomedical applications (e.g., for the treatment of glaucoma), most ergot alkaloids exhibit high toxicological risk and may even be lethal to humans and animals. Their pharmacological profile results from the structural similarity between lysergic acid-derived compounds and noradrenalin, dopamine, and serotonin neurotransmitters. To reduce their toxicological risk, while increasing their bioavailability, improved delivery systems were proposed. This review discusses the safety aspects of using ergot alkaloids in ocular pharmacology and proposes the development of lipid and polymeric nanoparticles for the topical administration of these drugs to enhance their therapeutic efficacy for the treatment of glaucoma.

In Vitro Characterization, Modelling, and Antioxidant Properties of Polyphenon-60 from Green Tea in Eudragit S100-2 Chitosan Microspheres.

Eudragit S100-coated chitosan microspheres (S100Ch) are proposed as a new oral delivery system for green tea polyphenon-60 (PP60). PP60 is a mixture of polyphenolic compounds, known for its active role in decreasing oxidative stress and metabolic risk factors involved in diabetes and in other chronic diseases. Chitosan-PP60 microspheres prepared by an emulsion cross-linking method were coated with Eudragit S100 to ensure the release of PP60 in the terminal ileum. Different core-coat ratios of Eudragit and chitosan were tested. Optimized chitosan microspheres were obtained with a chitosan:PP60 ratio of 8:1 (Ch-PP608:1), rotation speed of 1500 rpm, and surfactant concentration of 1.0% (m/v) achieving a mean size of 7.16 µm. Their coating with the enteric polymer (S100Ch-PP60) increased the mean size significantly (51.4 µm). The in vitro modified-release of PP60 from S100Ch-PP60 was confirmed in simulated gastrointestinal conditions. Mathematical fitting models were used to characterize the release mechanism showing that both Ch-PP608:1 and S100Ch-PP60 fitted the Korsmeyers-Peppas model. The antioxidant activity of PP60 was kept in glutaraldehyde-crosslinked chitosan microspheres before and after their coating, showing an IC50 of 212.3 µg/mL and 154.4 µg/mL, respectively. The potential of chitosan microspheres for the delivery of catechins was illustrated, with limited risk of cytotoxicity as shown in Caco-2 cell lines using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The beneficial effects of green tea and its derivatives in the management of metabolic disorders can be exploited using mucoadhesive chitosan microspheres coated with enteric polymers for colonic delivery.

Ocular Cell Lines and Genotoxicity Assessment.

Genotoxicity screening tests aim to evaluate if and to what extent a compound in contact with the human body (e.g., a drug molecule, a compound from the environment) interacts with DNA. The comet assay is a sensitive method used to predict the risk of DNA damage in individual cells, as it quantifies the tape breaks, being the alkaline version (pH > 13) the most commonly used in the laboratory. Epithelial cells serve as biomatrices in genotoxicity assessments. As ca. 80% of solid cancers are of epithelial origin, the quantification of the DNA damage upon exposure of epithelial cells to a drug or drug formulation becomes relevant. Comet assays run in epithelial cells also have clinical applications in human biomonitoring, which assesses whether and to what extent is the human body exposed to environmental genotoxic compounds and how such exposure changes over time. Ocular mucosa is particularly exposed to environmental assaults. This review summarizes the published data on the genotoxicity assessment in estimating DNA damage in epithelial cells with a special focus on ocular cell lines. General comet assay procedures for ex vivo and in vivo epithelium samples are also described.