Evaluation of epithelial transport and oxidative stress protection of nanoengineered curcumin derivative-cyclodextrin formulation for ocular delivery

The potential benefits of polyphenols for corneal diseases

The cornea functions as the primary barrier of the ocular surface, regulating temperature and humidity while providing protection against oxidative stress, harmful stimuli and pathogenic microorganisms. Corneal diseases can affect the biomechanical and optical properties of the eye, resulting in visual impairment or even blindness. Due to their diverse origins and potent biological activities, plant secondary metabolites known as polyphenols offer potential advantages for treating corneal diseases owing to their anti-inflammatory, antioxidant, and antibacterial properties. Various polyphenols and their derivatives have demonstrated diverse mechanisms of action in vitro and in vivo, exhibiting efficacy against a range of corneal diseases including repair of tissue damage, treatment of keratitis, inhibition of neovascularization, alleviation of dry eye syndrome, among others. Therefore, this article presents a concise overview of corneal and related diseases, along with an update on the research progress of natural polyphenols in safeguarding corneal health. A more comprehensive understanding of natural polyphenols provides a novel perspective for secure treatment of corneal diseases.

Investigation of Cannabinoid Acid/Cyclodextrin Inclusion Complex for Improving Physicochemical and Biological Performance

This study aimed to investigate the enhancement of cannabinoid acid solubility and stability through the formation of a cannabinoid acid/cyclodextrin (CD) inclusion complex. Two cannabinoid acids, tetrahydro-cannabinolic acid (THCA) and cannabidiolic acid (CBDA), were selected as a model drug along with five types of CD: α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and methylated-β-cyclodextrin (M-β-CD). Phase solubility studies were conducted using various types of CD to determine the complex stoichiometry. The preparation methods of the CD inclusion complex were optimized by adjusting the loading pH solution and the drying processes (spray-drying, freeze-drying, spray-freeze-drying). The drying process of the cannabinoid acid/M-β-CD inclusion complex was further optimized through the spray-freeze-drying method. These CD complexes were characterized using solubility determination, differential scanning calorimetry (DSC), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and 1H NMR spectroscopy. DSC, XRD, and FE-SEM studies confirmed the non-crystalline state of the cannabinoid acid/CD inclusion complex. The permeation of THCA or CBDA from the M-β-CD spray-freeze-dried inclusion complex was highly improved compared to those of cannabis ethanolic extracts under simulated physiological conditions. The stability of the cannabinoid acid/M-β-CD inclusion complex was maintained for 7 days in a simulated physiological condition. Furthermore, the minimum inhibitory concentration of cannabinoid acid/M-β-CD inclusion complex had superior anti-cancer activity in MCF-7 breast cancer cell lines compared to cannabinoid acid alone. The improved physicochemical and biological performances indicated that these CD inclusion complexes could provide a promising option for loading lipophilic cannabinoids in cannabis-derived drug products.

Polysaccharides-based nanocarriers enhance the anti-inflammatory effect of curcumin

Curcumin (CUR) has been discovered to have many biological activities, including anti-inflammatory, anti-cancer, anti-oxygenation, anti-human immunodeficiency virus, anti-microbial and exhibits a good effect on the prevention and treatment of many diseases. However, the limited properties of CUR, including the poor solubility, bioavailability and instability caused by enzymes, light, metal irons, and oxygen, have compelled researchers to turn their attention to drug carrier application to overcome these drawbacks. Encapsulation may provide potential protective effects to the embedding materials and/or have a synergistic effect with them. Therefore, nanocarriers, especially polysaccharides-based nanocarriers, have been developed in many studies to enhance the anti-inflammatory capacity of CUR. Consequently, it's critical to review current advancements in the encapsulation of CUR using polysaccharides-based nanocarriers, as well as further study the potential mechanisms of action where polysaccharides-based CUR nanoparticles (the complex nanoparticles/Nano CUR-delivery systems) exhibit their anti-inflammatory effects. This work suggests that polysaccharides-based nanocarriers will be a thriving field in the treatment of inflammation and inflammation-related diseases.

Advanced Glycation End-Products and Diabetic Neuropathy of the Retina

Diabetic retinopathy is a tissue-specific neurovascular impairment of the retina in patients with both type 1 and type 2 diabetes. Several pathological factors are involved in the progressive impairment of the interdependence between cells that consist of the neurovascular units (NVUs). The advanced glycation end-products (AGEs) are one of the major pathological factors that cause the impairments of neurovascular coupling in diabetic retinopathy. Although the exact mechanisms for the toxicities of the AGEs in diabetic retinopathy have not been definitively determined, the AGE-receptor of the AGE (RAGE) axis, production of reactive oxygen species, inflammatory reactions, and the activation of the cell death pathways are associated with the impairment of the NVUs in diabetic retinopathy. More specifically, neuronal cell death is an irreversible change that is directly associated with vision reduction in diabetic patients. Thus, neuroprotective therapies must be established for diabetic retinopathy. The AGEs are one of the therapeutic targets to examine to ameliorate the pathological changes in the NVUs in diabetic retinopathy. This review focuses on the basic and pathological findings of AGE-induced neurovascular abnormalities and the potential therapeutic approaches, including the use of anti-glycated drugs to protect the AGE-induced impairments of the NVUs in diabetic retinopathy.

A Novel Curcumin Arginine Salt: A Solution for Poor Solubility and Potential Anticancer Activities

Curcumin is a natural polyphenolic compound with well-known anticancer properties. Poor solubility and permeability hamper its use as an anticancer pharmaceutical product. In this study, L-arginine, a basic amino acid and a small hydrophilic molecule, was utilized to form a salt with the weak acid curcumin to enhance its solubility and potentiate the anticancer activities of curcumin. Two methods were adopted for the preparation of curcumin: L-arginine salt, namely, physical mixing and coprecipitation. The ion pair or salt was characterized for docking, solubility, DSC, FTIR, XRD, in vitro dissolution, and anticancer activities using MCF7 cell lines. The molecular docking suggested a salt/ion-pair complex between curcumin and L-arginine. Curcumin solubility was increased 335- and 440-fold by curcumin in L-arginine, physical, and co-precipitated mixtures, respectively. Thermal and spectral analyses supported the molecular docking and formation of a salt/ion pair between curcumin and L-arginine. The cytotoxicity of curcumin L-arginine salt significantly improved (p < 0.05) by 1.4-fold, as evidenced by the calculated IC50%, which was comparable to Taxol (the standard anticancer drug but with common side effects).

Polymeric/Dextran Wafer Dressings as Promising Long-Acting Delivery Systems for Curcumin Topical Delivery and Enhancing Wound Healing in Male Wistar Albino Rats

Curcumin is the main active constituent in turmeric, and it is one of the biopolyphenolic compounds. A cumulative body of research supports the use of curcumin in the treatment of wounds, yet poor water solubility and lack of therapeutic dose determination hamper its use for this therapeutic purpose. This work aimed at preparing novel curcumin wafer dressings to provide a favorable environment for wound healing. Hybrid synthetic (PVA, PVP, HPMC, and CMC) and biodegradable (sodium alginate and dextran) polymers were employed to prepare wafer dressings loaded with incremental three doses (2, 10, and 20 mg) of curcumin per a wafer dressing. The solvent casting method was used to prepare the dressings. Dimension, surface pH, mechanical properties, DSC, FTIR, XRD, erosion time, and in vitro release were studied. Skin wound healing assay was studied in Wistar albino rats. Six curcumin-loaded wafers were successfully prepared with good mechanical properties. Curcumin was dispersed in an amorphous/molecular form, as evidenced by thermal (DSC) and spectral (FTIR and XRD) analyses. Prolonged curcumin release (>24 h) was recorded for F6 (10 mg curcumin) and F7 (20 mg curcumin). Wound healing rate constants and time for 50% wound closure (T1/2) were estimated from a semi-log wound diameter versus time curve. A superior healing rate (up to 3-fold faster) was recorded for curcumin-loaded wafer dressings containing 10 mg (F6) with T1/2 of 7 days compared to 20 days for the placebo-treated group. These results warrant using the selected curcumin-loaded wafer dressing for safer and faster wound closure.

Biophysical Evaluation of Water-Soluble Curcumin Encapsulated in β-Cyclodextrins on Colorectal Cancer Cells

Curcumin (CUR), a curcuminoid originating from turmeric root, possesses diverse pharmacological applications, including potent anticancer properties. However, the use of this efficacious agent in cancer therapy has been limited due to low water solubility and poor bioavailability. To overcome these problems, a drug delivery system was established as an excipient allowing improved dispersion in aqueous media coupled with enhanced in vitro anticancer effects. Different analyses such as UV-vis spectroscopy, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solubility and dissolution assays were determined to monitor the successful encapsulation of CUR within the inner cavity of a β-cyclodextrin (β-CD) complex. The results indicated that water solubility was improved by 205.75-fold compared to pure CUR. Based on cytotoxicity data obtained from MTT assays, the inclusion complex exhibited a greater decrease in cancer cell viability compared to pure CUR. Moreover, cancer cell migration rates were decreased by 75.5% and 38.92%, invasion rates were decreased by 37.7% and 35.7%, while apoptosis rates were increased by 26.3% and 14.2%, and both caused caspase 3 activation toward colorectal cancer cells (SW480 and HCT116 cells). This efficacious formulation that enables improved aqueous dispersion is potentially useful and can be extended for various chemotherapeutic applications. Preliminary toxicity evaluation also indicated that its composition can be safely used in humans for cancer therapy.

Design, Preparation and Evaluation of Supramolecular Complexes with Curcumin for Enhanced Cytotoxicity in Breast Cancer Cell Lines

Curcumin is one of the most researched phytochemicals by pharmacologists and formulation scientists to unleash its potential therapeutic benefits and tackle inherent biopharmaceutic problems. In this study, the native β-cyclodextrin (CD) and three derivatives, namely, Captisol (sulfobutyl ether β-CD), hydroxypropyl β-cyclodextrin, and hydroxyethyl β-cyclodextrin were investigated for inclusion complexes with curcumin using two preparation methods (physical mixing and solvent evaporation). The prepared complexes were studied for docking, solubility, FTIR, DSC, XRD, and dissolution rates. The best-fitting curcumin: cyclodextrins (the latter of the two CDs) were evaluated for cytotoxicity using human breast cell lines (MCF-7). Dose-dependent cytotoxicity was recorded as IC50% for curcumin, curcumin: hydroxyethyl β-cyclodextrin, and curcumin: hydroxypropyl β-cyclodextrin were 7.33, 7.28, and 19.05 µg/mL, respectively. These research findings indicate a protective role for the curcumin: hydroxypropyl β-cyclodextrin complex on the direct cell lines of MCF-7.

Recent Developments of Nanostructures for the Ocular Delivery of Natural Compounds

Ocular disorders comprising various diseases of the anterior and posterior segments are considered as the main reasons for blindness. Natural products have been identified as potential treatments for ocular diseases due to their anti-oxidative, antiangiogenic, and anti-inflammatory effects. Unfortunately, most of these beneficial compounds are characterised by low solubility which results in low bioavailability and rapid systemic clearance thus requiring frequent administration or requiring high doses, which hinders their therapeutic applications. Additionally, the therapeutic efficiency of ocular drug delivery as a popular route of drug administration for the treatment of ocular diseases is restricted by various anatomical and physiological barriers. Recently, nanotechnology-based strategies including polymeric nanoparticles, micelles, nanofibers, dendrimers, lipid nanoparticles, liposomes, and niosomes have emerged as promising approaches to overcome limitations and enhance ocular drug bioavailability by effective delivery to the target sites. This review provides an overview of nano-drug delivery systems of natural compounds such as thymoquinone, catechin, epigallocatechin gallate, curcumin, berberine, pilocarpine, genistein, resveratrol, quercetin, naringenin, lutein, kaempferol, baicalin, and tetrandrine for ocular applications. This approach involves increasing drug concentration in the carriers to enhance drug movement into and through the ocular barriers.

Complexation of phytochemicals with cyclodextrins and their derivatives- an update

Bioactive phytochemicals from natural source have gained tremendous interest over several decades due to their wide and diverse therapeutic activities playing key role as functional food supplements, pharmaceutical and nutraceutical products. Nevertheless, their application as therapeutically active moieties and formulation into novel drug delivery systems are hindered due to major drawbacks such as poor solubility, bioavailability and dissolution rate and instability contributing to reduction in bioactivity. These drawbacks can be effectively overcome by their complexation with different cyclodextrins. Present article discusses complexation of phytochemicals varying from flavonoids, phenolics, triterpenes, and tropolone with different natural and synthetic cyclodextrins. Moreover, the article summarizes complexation methods, complexation efficiency, stability, stability constants and enhancement in rate and extent of dissolution, bioavailability, solubility, in vivo and in vitro activities of reported complexed phytochemicals. Additionally, the article presents update of published patent details comprising of complexed phytochemicals of therapeutic significance. Thus, phytochemical cyclodextrin complexes have tremendous potential for transformation into drug delivery systems as substantiated by significant outcome of research findings.

Assessment of the Anti-inflammatory Effects of NORFLO® ORO in Acute Relapses of HLA-B27-associated Autoimmune Uveitis: A Multicenter, Randomized, Placebo-controlled, Double-blind Clinical Study

BACKGROUND

An effective therapy to reduce the number and severity of HLA-B27-related acute anterior uveitis (AAU) recurrences represents a clinical need. Curcumin is a promising therapeutic option in various inflammatory eye diseases. To enhance its absorption and eye tissue selectivity, a phospholipidic-curcumin complex (PHBC) has been formulated (Iphytoone®, Eye Pharma S.p.A.).

AIMS

This study investigates if PHBC is effective and safe to decrease the number and intensity of HLA-B27-related AAU relapses.

METHODS

HLA-B27-related AAU patients were randomly divided to receive PHBC or placebo for 12 months (NCT03584724).

RESULTS

Compared with the previous year, the number of relapses decreased in both groups. The proportion of responders was significantly higher in the PBHC group. The severity of attacks was comparable. The study drug was well tolerated.

CONCLUSIONS

A beneficial effect of PHBC treatment is suggested because the proportion of responders was significantly higher in this group of patients.

Role of Curcumin in Retinal Diseases-A review

PURPOSE

To review the role of curcumin in retinal diseases, COVID era, modification of the molecule to improve bioavailability and its future scope.

METHODS

PubMed and MEDLINE searches were pertaining to curcumin, properties of curcumin, curcumin in retinal diseases, curcumin in diabetic retinopathy, curcumin in age-related macular degeneration, curcumin in retinal and choroidal diseases, curcumin in retinitis pigmentosa, curcumin in retinal ischemia reperfusion injury, curcumin in proliferative vitreoretinopathy and curcumin in current COVID era.

RESULTS

In experimental models, curcumin showed its pleiotropic effects in retinal diseases like diabetic retinopathy by increasing anti-oxidant enzymes, upregulating HO-1, nrf2 and reducing or inhibiting inflammatory mediators, growth factors and by inhibiting proliferation and migration of retinal endothelial cells in a dose-dependent manner in HRPC, HREC and ARPE-19 cells. In age-related macular degeneration, curcumin acts by reducing ROS and inhibiting apoptosis inducing proteins and cellular inflammatory genes and upregulating HO-1, thioredoxin and NQO1. In retinitis pigmentosa, curcumin has been shown to delay structural defects of P23H gene in P23H-rhodopsin transgenic rats. In proliferative vitreoretinopathy, curcumin inhibited the action of EGF in a dose- and time-dependent manner. In retinal ischemia reperfusion injury, curcumin downregulates IL-17, IL-23, NF_KB, STAT-3, MCP-1 and JNK. In retinoblastoma, curcumin inhibits proliferation, migration and apoptosis of RBY79 and SO-RB50. Curcumin has already proven its efficacy in inhibiting viral replication, coagulation and cytokine storm in COVID era.

CONCLUSION

Curcumin is an easily available spice used traditionally in Indian cooking. The benefits of curcumin are manifold, and large randomized controlled trials are required to study its effects not only in treating retinal diseases in humans but in their prevention too.

Combined Application of Prototype Ultrasound and BSA-Loaded PLGA Particles for Protein Delivery

PURPOSE

To develop an in vitro culture system for tissue engineering to mimic the in vivo environment and evaluate the applicability of ultrasound and PLGA particle system.

METHODS

For tissue engineering, large molecules such as growth factors for cell differentiation should be supplied in a controlled manner into the culture system, and the in vivo microenvironment need to be reproduced in the system for the regulation of cellular function. In this study, portable prototype ultrasound with low intensity was devised and tested for protein release from bovine serum albumin (BSA)-loaded poly(lactic-co-glycolic acid) (PLGA) particles.

RESULTS

BSA-loaded PLGA particles were prepared using various types of PLGA reagents and their physicochemical properties were characterized including particle size, shape, or aqueous wetting profiles. The BSA-loaded formulation showed nano-ranged size distribution with optimal physical stability during storage period, and protein release behaviors in a controlled manner. Notably, the application of prototype ultrasound with low intensity influenced protein release patterns in the culture system containing the BSA-loaded PLGA formulation. The results revealed that the portable ultrasound set controlled by the computer could contribute for the protein delivery in the culture medium.

CONCLUSIONS

This study suggests that combined application with ultrasound and protein-loaded PLGA encapsulation system could be utilized to improve culture system for tissue engineering or cell regeneration therapy.

Synergistic Effect of Growth Factor Releasing Polymeric Nanoparticles and Ultrasound Stimulation on Osteogenic Differentiation

Mesenchymal stem cells (MSCs) have been extensively used in the tissue regeneration therapy. Ex vivo therapy with well-differentiated osteogenic cells is known as an efficient treatment for musculoskeletal diseases, including rheumatoid diseases. However, along with its high cost, the current therapy has limitations in terms of restoring bone regeneration procedures. An efficient process for the cell differentiation to obtain a large number of functionalized osteogenic cells is necessary. Therefore, it is strongly recommended to develop strategies to produce sufficient numbers of well-differentiated osteogenic cells from the MSCs. In general, differentiation media with growth factors have been used to facilitate cell differentiation. In the present study, the poly (lactic-co-glycolic acid) (PLGA) nanoparticles incorporating the growth factors were included in the media, resulting in releasing growth factors (dexamethasone and β-glycerophosphate) in the media in the controlled manner. Stable growth and early differentiation of osteogenic cells were achieved by the PLGA-based growth factor releasing system. Moreover, low intensity pulsed ultrasound was applied to this system to induce cell differentiation process. The results revealed that, as a biomarker at early stage of osteogenic cell differentiation, Lamin A/C nuclear protein was efficiently expressed in the cells growing in the presence of PLGA-based growth factor reservoirs and ultrasound. In conclusion, our results showed that the ultrasound stimulation combined with polymeric nanoparticles releasing growth factors could potentially induce osteogenic cell differentiation.

Curcumin In Situ Gelling Polymeric Insert with Enhanced Ocular Performance

The search for an ocular drug delivery system that could provide long-acting effects without a detriment to the anatomy and physiology of the eye remains a challenge. Polyphenolic compounds (curcumin in particular) have recently gained popularity due to their powerful antioxidant properties; yet curcumin suffers poor stability and water solubility. A conventional eye drop formulation of curcumin in the form of a suspension is likely to suffer a short duration of action requiring multiple instillations. On the other hand, polymeric in-situ gelling inserts offer the prospect of overcoming these limitations. The aim of this study was to prepare, characterize and evaluate in vivo, polymeric, in-situ gelling and mucoadhesive inserts for ocular surface delivery of curcumin. Different types and ratios of biocompatible polymers (HPMC, CMC, PL 127 and PVA) and three plasticizers along with the solvent casting method were adopted to prepare curcumin inserts. The inserts were investigated for their physicochemical characteristics, applicability, and suitability of use for potential placement on the ocular surface. The prepared inserts revealed that curcumin was mainly dispersed in the molecular form. Insert surfaces remained smooth and uniform without cracks appearing during preparation and thereafter. Improved mechanical and mucoadhesive properties, enhanced in vitro release (7.5- to 9-fold increases in RRT₃₀₀ min) and transcorneal permeation (5.4- to 8.86-fold increases in Papp) of curcumin was achieved by selected in-situ gelling inserts compared to a control curcumin suspension. The developed inserts demonstrated acceptable ocular tolerability, enhanced corneal permeability, and sustained release of curcumin along with retention of insert formulation F7 on the ocular surface for at least two-hours. This insert provides a viable alternative to conventional eye drop formulations of curcumin.

Highly Stable and Fine-Textured Hybrid Microspheres for Entrapment of Cosmetic Active Ingredients

This study details the preparation and application of supramolecular host-guest inclusion complexes entrapping biomineralized microspheres for long-term storage and their pH-responsive behavior. The microspheres were assembled using a CaCO₃ synthesis process coupled with cyclodextrin-tetrahydrocurcumin (CD-THC) inclusion complexes, forming fine-textured and mechanically stable hybrid materials. The products were successfully characterized using field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and particle size analysis (PSA). Various parameters such as the Brunauer-Emmett-Teller (BET) surface area, single point total pore volume, and pore size via adsorption/desorption analysis were also determined. The obtained THC-entrapped hybrid microspheres contained as high as 20 wt % THC loading and were very stable, preserving 90% of the initial concentration over four weeks of storage at different temperatures, largely limiting THC leaching and indicating high stability in a physiological environment. In addition, the pH-responsive release of THC from the hybrid microspheres was observed, showing potential use for application to weakly acidic skin surfaces. To our knowledge, this is the first demonstration of antiaging cosmetic formulation technology using biomineralization based on the co-synthesis of CaCO₃ and CD-THC complexes.

Reductive metabolites of curcumin and their therapeutic effects

Curcumin, a secondary metabolite from the turmeric plant is one of the most promising natural products, which has been studied extensively for decades. It has demonstrated several pharmacological activities in vitro and in vivo. Various studies have indicated that the pharmacological activity of curcumin is contributed by its metabolites. The aim of this review is to present an overview of metabolic products of curcumin produced upon its reduction like di, tetra, hexa and octa-hydrocurcumin. In addition, this paper has systematically analyzed the current information regarding medicinal use of reduced metabolites of curcumin and identified the limitations which have hindered its widespread usage in the medical world. Several diverse therapeutic effects have shown to be exhibited by reduced metabolites of curcumin such as antioxidant, anti-cancerous, anti-inflammatory and immunoregulatory activities. The potential underlying molecular mechanisms of the biological activities of reduced metabolites of curcumin have also been highlighted, which may provide insight into the principle of effectiveness of curcumin.

New resveratrol micelle formulation for ocular delivery: characterization and in vitro/in vivo evaluation

Many eye diseases, such as corneal wound healing after injury, involve oxidative stress and inflammatory responses; however, many efficient natural antioxidants (e.g. resveratrol) have limited application in ophthalmology due to their poor solubility, low stability and poor ocular bioavailability. In this work, the aim was to formulate resveratrol into a micelle ophthalmic solution for efficient delivery to the eye. A Soluplus micelle ophthalmic solution containing resveratrol (Sol-Res) was formulated and optimized with a small and uniform dispersion in an ophthalmic solution. Sol-Res did not show any cell toxicity but promoted cell proliferation in both the short- and long-term cytotoxicity tests. The in vivo eye irritation test also verified the well ocular tolerance of the Sol-Res ophthalmic solution. The chemical stability of resveratrol in micelles in an aqueous solution was greatly improved over the free resveratrol solution, and Sol-Res also showed a good storage stability in the short-term storage stability test. Sol-Res showed improved in vitro passive permeation, in vitro cellular uptake, and in vivo corneal permeation over the free Res suspension solution. Furthermore, Sol-Res favored in vivo corneal wound healing, and the inhibition of key anti-inflammation mediators and the production of antioxidant factors in mRNA expression was observed in the Sol-Res treated wound healing corneas, suggesting that the mechanisms that regulate proinflammatory cytokines and oxidative stress might be involved in its therapeutic effect. Therefore, Sol-Res might be a promising candidate for further clinical application.

ICG-Loaded PEGylated BSA-Silver Nanoparticles for Effective Photothermal Cancer Therapy

Purpose

Indocyanine green (ICG), a near infrared (NIR) dye clinically approved in medical diagnostics, possesses great heat conversion efficiency, which renders itself as an effective photosensitizer for photothermal therapy (PTT) of cancer. However, there remain bottleneck challenges for use in PTT, which are the poor photo and plasma stability of ICG. To address these problems, in this research, ICG-loaded silver nanoparticles were prepared and evaluated for the applicability as an effective agent for photothermal cancer therapy.

Methods and Results

PEGylated bovine serum albumin (BSA)-coated silver core/shell nanoparticles were synthesized with a high loading of ICG (“PEG-BSA-AgNP/ICG”). Physical characterization was carried out using size analyzer, transmission electron microscopy, and Fourier transform infrared spectrophotometry to identify successful preparation and size stability. ICG-loading content and the photothermal conversion efficiency of the particles were confirmed with inductively coupled plasma mass spectrometry and laser instruments. In vitro studies showed that the PEG-BSA-AgNP/ICG could provide great photostability for ICG, and their applicability for PTT was verified from the cellular study results. Furthermore, when the PEG-BSA-AgNP/ICG were tested in vivo, study results exhibited that ICG could stably remain in the blood circulation for a markedly long period (plasma half-life: 112 min), and about 1.7% ID/g tissue could be accumulated in the tumor tissue at 4 h post-injection. Such nanoparticle accumulation in the tumor enabled tumor surface temperature to be risen to 50°C (required for photo-ablation) by laser irradiation and led to successful inhibition of tumor growth in the B16F10 s.c. syngeneic nude mice model, with minimal systemic toxicity.

Conclusion

Our findings demonstrated that PEG-BSA-AgNPs could serve as effective carriers for delivering ICG to the tumor tissue with great stability and safety.

Curcumin as a Therapeutic Option in Retinal Diseases

The retina is subjected to oxidative stress due to its high vascularization, long time light exposition and a high density of mitochondria. Oxidative stress can lead to pathological processes, like cell apoptosis, angiogenesis and inflammation ending in retinal pathologies. Curcumin, a major bioactive component obtained from the spice turmeric (Curcuma longa) rhizome has been used for centuries in Asian countries for cooking and for curing all kinds of diseases like dysentery, chest congestion and pain in general, due to its antioxidant effects. Curcumin prevents the formation of reactive oxygen species and so it is a good protective agent. Curcumin has shown also anti-inflammatory, and antitumor properties. Curcumin is a natural product, which can be a therapeutic option in a variety of retinal diseases due to its pleiotropic properties. Some drawbacks are its poor solubility, bioavailability and lack of stability at physiological conditions; which have been shown in curcumin skeptical publications. In this review, we provide some lights and shadows on curcumin administration on the major retinal pathologies.

Nanoparticles Targeting Macrophages as Potential Clinical Therapeutic Agents Against Cancer and Inflammation

With the development of nanotechnology, significant progress has been made in the design, and manufacture of nanoparticles (NPs) for use in clinical treatments. Recent increases in our understanding of the central role of macrophages in the context of inflammation and cancer have reinvigorated interest in macrophages as drug targets. Macrophages play an integral role in maintaining the steady state of the immune system and are involved in cancer and inflammation processes. Thus, NPs tailored to accurately target macrophages have the potential to transform disease treatment. Herein, we first present a brief background information of NPs as drug carriers, including but not limited to the types of nanomaterials, their biological properties and their advantages in clinical application. Then, macrophage effector mechanisms and recent NPs-based strategies aimed at targeting macrophages by eliminating or re-educating macrophages in inflammation and cancer are summarized. Additionally, the development of nanocarriers targeting macrophages for disease diagnosis is also discussed. Finally, the significance of macrophage-targeting nanomedicine is highlighted, with the goal of facilitating future clinical translation.