Proof-of-Concept Study of Multifunctional Hybrid Nanoparticle System Combined with NIR Laser Irradiation for the Treatment of Melanoma.

The global impact of cancer emphasizes the importance of developing innovative, effective and minimally invasive therapies. In the context of superficial cancers, the development of a multifunctional nanoparticle-based system and its in vitro and in vivo safety and efficacy characterization are, herein, proposed as a proof-of-concept. This multifunctional system consists of gold nanoparticles coated with hyaluronic and oleic acids, and functionalized with epidermal growth factor for greater specificity towards cutaneous melanoma cells. This nanoparticle system is activated by a near-infrared laser. The characterization of this nanoparticle system included several phases, with in vitro assays being firstly performed to assess the safety of gold nanoparticles without laser irradiation. Then, hairless immunocompromised mice were selected for a xenograft model upon inoculation of A375 human melanoma cells. Treatment with near-infrared laser irradiation for five minutes combined with in situ administration of the nanoparticles showed a tumor volume reduction of approximately 80% and, in some cases, led to the formation of several necrotic foci, observed histologically. No significant skin erythema at the irradiation zone was verified, nor other harmful effects on the excised organs. In conclusion, these assays suggest that this system is safe and shows promising results for the treatment of superficial melanoma.

Current Trends in Cancer Nanotheranostics: Metallic, Polymeric, and Lipid-Based Systems.

Theranostics has emerged in recent years to provide an efficient and safer alternative in cancer management. This review presents an updated description of nanotheranostic formulations under development for skin cancer (including melanoma), head and neck, thyroid, breast, gynecologic, prostate, and colon cancers, brain-related cancer, and hepatocellular carcinoma. With this focus, we appraised the clinical advantages and drawbacks of metallic, polymeric, and lipid-based nanosystems, such as low invasiveness, low toxicity to the surrounding healthy tissues, high precision, deeper tissue penetration, and dosage adjustment in a real-time setting. Particularly recognizing the increased complexity and multimodality in this area, multifunctional hybrid nanoparticles, comprising different nanomaterials and functionalized with targeting moieties and/or anticancer drugs, present the best characteristics for theranostics. Several examples, focusing on their design, composition, imaging and treatment modalities, and in vitro and in vivo characterization, are detailed herein. Briefly, all studies followed a common trend in the design of these theranostics modalities, such as the use of materials and/or drugs that share both inherent imaging (e.g., contrast agents) and therapeutic properties (e.g., heating or production reactive oxygen species). This rationale allows one to apparently overcome the heterogeneity, complexity, and harsh conditions of tumor microenvironments, leading to the development of successful targeted therapies.

Anticancer properties of the abietane diterpene 6,7-dehydroroyleanone obtained by optimized extraction.

AIM: 6,7-dehydroroyleanone (DHR) is a cytotoxic abietane present in the essential oil of Plectranthus madagascariensis. METHODS/RESULTS: Different extraction parameters were tested, and its extraction optimization was accomplished with a Clevenger apparatus-based hydrodistillation. After isolation, its effect on microtubules, P-glycoprotein and caspases was assessed on several cell lines and the compound was coupled with hybrid nanoparticles. The results show that DHR does not interfere with microtubule formation, but evades the resistance mechanisms of P-glycoprotein. Strong activation of caspases-3 and -9 indicates that DHR is able to induce apoptosis by triggering the intrinsic cell death pathway. Moreover, the assembly of DHR with hybrid nanoparticles was able to potentiate the effect of DHR in cancer cells. CONCLUSION: DHR seems to be a promising starting material with anticancer properties to further be explored.

Design and evaluation of novel topical formulation with olive oil as natural functional active.

Currently, the innovative skin research is focused on the development of novel topical formulations loaded with natural functional actives. The health benefits of olive oil are unsurpassed and many others are revealed as research studies allow the understanding of its unlimited properties. Olive oil has a protective toning effect on skin, but it is not transported effectively into its layers. Aiming the development of a cosmetic formulation for skin photoprotection and hydration, we have prepared and characterized macro-sized particles, made of a hydrogel polymer, loaded with olive oil. Alginate beads were uniform in shape, with minimal oil leakage, offering interesting prospects for encapsulation of lipophilic and poorly stable molecules, like olive oil. In vitro photoprotection and in vivo tolerance tests were in favor of this application. Thus, this study suggests that the incorporation of the olive oil-loaded particles into a cream formulation provides strong moisturizing properties and a photoprotective potential, when applied to healthy subjects.

EGF Functionalized Polymer-Coated Gold Nanoparticles Promote EGF Photostability and EGFR Internalization for Photothermal Therapy.

The application of functionalized nanocarriers on photothermal therapy for cancer ablation has wide interest. The success of this application depends on the therapeutic efficiency and biocompatibility of the system, but also on the stability and biorecognition of the conjugated protein. This study aims at investigating the hypothesis that EGF functionalized polymer-coated gold nanoparticles promote EGF photostability and EGFR internalization, making these conjugated particles suitable for photothermal therapy. The conjugated gold nanoparticles (100-200 nm) showed a plasmon absorption band located within the near-infrared range (650-900 nm), optimal for photothermal therapy applications. The effects of temperature, of polymer-coated gold nanoparticles and of UVB light (295nm) on the fluorescence properties of EGF have been investigated with steady-state and time-resolved fluorescence spectroscopy. The fluorescence properties of EGF, including the formation of Trp and Tyr photoproducts, is modulated by temperature and by the intensity of the excitation light. The presence of polymeric-coated gold nanoparticles reduced or even avoided the formation of Trp and Tyr photoproducts when EGF is exposed to UVB light, protecting this way the structure and function of EGF. Cytotoxicity studies of conjugated nanoparticles carried out in normal-like human keratinocytes showed small, concentration dependent decreases in cell viability (0-25%). Moreover, conjugated nanoparticles could activate and induce the internalization of overexpressed Epidermal Growth Factor Receptor in human lung carcinoma cells. In conclusion, the gold nanoparticles conjugated with Epidermal Growth Factor and coated with biopolymers developed in this work, show a potential application for near infrared photothermal therapy, which may efficiently destroy solid tumours, reducing the damage of the healthy tissue.

Functionalized diterpene parvifloron D-loaded hybrid nanoparticles for targeted delivery in melanoma therapy.

AIM: Parvifloron D is a natural diterpene with a broad and not selective cytotoxicity toward human tumor cells. In order to develop a targeted antimelanoma drug delivery platform for Parvifloron D, hybrid nanoparticles were prepared with biopolymers and functionalized with α-melanocyte stimulating hormone. Results/methodology: Nanoparticles were produced according to a solvent displacement method and the physicochemical properties were assessed. It was shown that Parvifloron D is cytotoxic and can induce, both as free and as encapsulated drug, cell death in melanoma cells (human A375 and mouse B16V5). Parvifloron D-loaded nanoparticles showed a high encapsulation efficiency (87%) and a sustained release profile. In vitro experiments showed the nanoparticles' uptake and cell internalization. CONCLUSION: Hybrid nanoparticles appear to be a promising platform for long-term drug release, presenting the desired structure and a robust performance for targeted anticancer therapy.

Bioproduction of gold nanoparticles for photothermal therapy.

BACKGROUND: Photothermal response of plasmonic nanomaterials can be utilized for a number of therapeutic applications such as the ablation of solid tumors. METHODS & RESULTS: Gold nanoparticles were prepared using different methods. After optimization, we applied an aqueous plant extract as the reducing and capping agent of gold and maximized the near-infrared absorption (650-900 nm). Resultant nanoparticles showed good biocompatibility when tested in vitro in human keratinocytes and yeast Saccharomyces cerevisiae. Gold nanoparticles were easily activated by controlled temperature with an ultrasonic water bath and application of a pulsed laser. CONCLUSION: These gold nanoparticles can be synthesized with reproducibility, modified with seemingly limitless chemical functional groups, with adequate controlled optical properties for laser phototherapy of tumors and targeted drug delivery.

Polymeric nanoparticles modified with fatty acids encapsulating betamethasone for anti-inflammatory treatment.

Topical glucocorticosteroids were incorporated into nanocarrier-based formulations, to overcome side effects of conventional formulations and to achieve maximum skin deposition. Nanoparticulate carriers have the potential to prolong the anti-inflammatory effect and provide higher local concentration of drugs, offering a better solution for treating dermatological conditions and improving patient compliance. Nanoparticles were formulated with poly-ϵ-caprolactone as the polymeric core along with stearic acid as the fatty acid, for incorporation of betamethasone-21-acetate. Oleic acid was applied as the coating fatty acid. Improvement of the drug efficacy, and reduction in drug degradation with time in the encapsulated form was examined, while administering it locally through controlled release. Nanoparticles were spherical with mean size of 300 nm and negatively charged surface. Encapsulation efficiency was 90%. Physicochemical stability in aqueous media of the empty and loaded nanoparticles was evaluated for six months. Drug degradation was reduced compared to free drug, after encapsulation into nanoparticles, avoiding the potency decline and promoting a controlled drug release over one month. Fourier transform infrared spectroscopy and thermal analysis confirmed drug entrapment, while cytotoxicity studies performed in vitro on human keratinocytes, Saccharomyces cerevisiae models and Artemia salina, showed a dose-response relationship for nanoparticles and free drug. In all models, drug loaded nanoparticles had a greater inhibitory effect. Nanoparticles increased drug permeation into lipid membranes in vitro. Preliminary safety and permeation studies conducted on rats, showed betamethasone-21-acetate in serum after 48 h application of a gel containing nanoparticles. No skin reactions were observed. In conclusion, the developed nanoparticles may be applied as topical treatment, after encapsulation of betamethasone-21-acetate, as nanoparticles promote prolonged drug release, increase drug stability in aqueous media, reducing drug degradation, and increase drug permeability through lipid membranes.