Natural rubber latex-based biomaterials for drug delivery and regenerative medicine: Trends and directions.

Natural Rubber Latex (NRL) has shown to be a promising biomaterial for use as a drug delivery system to release various bioactive compounds. It is cost-effective, easy to handle, biocompatible, and exhibits pro-angiogenic and pro-healing properties for both soft and hard tissues. NRL releases compounds following burst and sustained release kinetics, exhibiting first-order release kinetics. Moreover, its pore density can be adjusted for tailored kinetics profiles. In addition, biotechnological applications of NRL in amblyopia, smart mattresses, and neovaginoplasty have demonstrated success. This comprehensive review explores NRL's diverse applications in biotechnology and biomedicine, addressing challenges in translating research into clinical practice. Organized into eight sections, the review emphasizes NRL's potential in wound healing, drug delivery, and metallic nanoparticle synthesis. It also addresses the challenges in enhancing NRL's physical properties and discusses its interactions with the human immune system. Furthermore, examines NRL's potential in creating wearable medical devices and biosensors for neurological disorders. To fully explore NRL's potential in addressing important medical conditions, we emphasize throughout this review the importance of interdisciplinary research and collaboration. In conclusion, this review advances our understanding of NRL's role in biomedical and biotechnological applications, offering insights into its diverse applications and promising opportunities for future development.

Recent advances and perspectives on natural latex serum and its fractions for biomedical applications.

Advances and the discovery of new biomaterials have opened new frontiers in regenerative medicine. These biomaterials play a key role in current medicine by improving the life quality or even saving the lives of millions of people. Since the 2000s, Natural Rubber Latex (NRL) has been employed as wound dressings, mechanical barrier for Guided Bone Regeneration (GBR), matrix for drug delivery, and grafting. NRL is a natural polymer that can stimulate cell proliferation, neoangiogenesis, and extracellular matrix (ECM) formation. Furthermore, it is well established that proteins and other biologically active molecules present in the Natural Latex Serum (NLS) are responsible for the biological properties of NRL. NLS can be obtained from NRL by three main methods, namely (i) Centrifugation (fractionation of NRL in distinct fractions), (ii) Coagulation and sedimentation (coagulating NRL to separate the NLS from rubber particles), and (iii) Alternative extraction process (elution from NRL membrane). In this review, the chemical composition, physicochemical properties, toxicity, and other biological information such as osteogenesis, vasculogenesis, adhesion, proliferation, antimicrobial behavior, and antitumoral activity of NLS, as well as some of its medical instruments and devices are discussed. The progress in NLS applications in the biomedical field, more specifically in cell cultures, alternative animals, regular animals, and clinical trials are also discussed. An overview of the challenges and future directions of the applications of NLS and its derivatives in tissue engineering for hard and soft tissue regeneration is also given.

Biocompatible anti-aging face mask prepared with curcumin and natural rubber with antioxidant properties.

Natural rubber latex (NRL) is a biopolymer widely used in biomedical applications. In this work, we propose an innovative cosmetic face mask, combining the NRL's biological properties with curcumin (CURC), which has a high level of antioxidant activity (AA) to provide anti-aging benefits. Chemical, mechanical and morphological characterizations were performed. The CURC released by the NRL was evaluated by permeation in Franz cells. Cytotoxicity and hemolytic activity assays were performed to assess safety. The findings showed that the biological properties of CURC were preserved after loading in the NRL. About 44.2 % of CURC was released within the first six hours, and in vitro permeation showed that 9.36 % ± 0.65 was permeated over 24h. CURC-NRL was associated with a metabolic activity higher than 70 % in 3 T3 fibroblasts, cell viability ≥95 % in human dermal fibroblasts, and a hemolytic rate ≤ 2.24 % after 24 h. Furthermore, CURC-NRL maintained the mechanical characteristics (range suitable) for human skin application. We observed that CURC-NRL preserved ~20 % antioxidant activity from curcumin-free after loading in the NRL. Our results suggest that CURC-NRL has the potential to be used in the cosmetics industry, and the experimental methodology utilized in this study can be applied to different kinds of face masks.

Local administration of curcumin-loaded nanoparticles enhances periodontal repair in vivo.

The aim was to assess the influence of local application of curcumin-loaded nanoparticles on an experimental model of periodontal repair. Periodontitis was induced by ligatures on both lower first molars of rats. After 15 days, ligatures were removed ("treatment") and animals were randomly allocated to three experimental groups (n = 8/group): (i) 0.05 mg/ml curcumin-loaded nanoparticles, (ii) empty nanoparticles (vehicle control), and (iii) sterile saline (negative control). Experimental treatments were administered locally on days 0, 3, 5, 7, 9, and 11 after ligature removal. Animals were euthanized at 7 and 14 days. Bone repair was assessed by microcomputer tomography (µCT). Histological sections were stained with hematoxylin/eosin (H/E), Picrosirius Red, and Masson's trichrome. Expression of Runx-2 was studied by immunohistochemistry. Gene expression of Itgam, Arg1, and Inos was assessed by RT-qPCR. At 7 days, there was increased gene expression of Itgam and Arg1 and of the relative expression of Arg1/Inos in curcumin-treated animals, but no difference in any other outcomes. At 14 days, curcumin-loaded nanoparticles significantly increased bone repair and collagen content, as well as the number of osteocytes, percentage of extracellular matrix, and expression of Runx2. The results demonstrate that local administration of curcumin-loaded nanoparticles enhanced tissue repair in an experimental model of periodontal repair. Nanoparticle-encapsulated curcumin enhances early post-treatment repair of periodontal tissues.

Development of Biotechnological Photosensitizers for Photodynamic Therapy: Cancer Research and Treatment-From Benchtop to Clinical Practice.

Photodynamic therapy (PDT) is a noninvasive therapeutic approach that has been applied in studies for the treatment of various diseases. In this context, PDT has been suggested as a new therapy or adjuvant therapy to traditional cancer therapy. The mode of action of PDT consists of the generation of singlet oxygen (¹O2) and reactive oxygen species (ROS) through the administration of a compound called photosensitizer (PS), a light source, and molecular oxygen (3O2). This combination generates controlled photochemical reactions (photodynamic mechanisms) that produce ROS, such as singlet oxygen (¹O2), which can induce apoptosis and/or cell death induced by necrosis, degeneration of the tumor vasculature, stimulation of the antitumor immune response, and induction of inflammatory reactions in the illuminated region. However, the traditional compounds used in PDT limit its application. In this context, compounds of biotechnological origin with photosensitizing activity in association with nanotechnology are being used in PDT, aiming at its application in several types of cancer but with less toxicity toward neighboring tissues and better absorption of light for more aggressive types of cancer. In this review, we present studies involving innovatively developed PS that aimed to improve the efficiency of PDT in cancer treatment. Specifically, we focused on the clinical translation and application of PS of natural origin on cancer.

Tissue Engineering and Photodynamic Therapy: A New Frontier of Science for Clinical Application -An Up-To-Date Review.

Tissue engineering (TE) connects principles of life sciences and engineering to develop biomaterials as alternatives to biological systems and substitutes that can improve and restore tissue function. The principle of TE is the incorporation of cells through a 3D matrix support (scaffold) or using scaffold-free organoid cultures to reproduce the 3D structure. In addition, 3D models developed can be used for different purposes, from studies mimicking healthy tissues and organs as well as to simulate and study different pathologies. Photodynamic therapy (PDT) is a non-invasive therapeutic modality when compared to conventional therapies. Therefore, PDT has great acceptance among patients and proves to be quite efficient due to its selectivity, versatility and therapeutic simplicity. The PDT mechanism consists of the use of three components: a molecule with higher molar extinction coefficient at UV-visible spectra denominated photosensitizer (PS), a monochromatic light source (LASER or LED) and molecular oxygen present in the microenvironment. The association of these components leads to a series of photoreactions and production of ultra-reactive singlet oxygen and reactive oxygen species (ROS). These species in contact with the pathogenic cell, leads to its target death based on necrotic and apoptosis ways. The initial objective of PDT is the production of high concentrations of ROS in order to provoke cellular damage by necrosis or apoptosis. However, recent studies have shown that by decreasing the energy density and consequently reducing the production of ROS, it enabled a specific cell response to photostimulation, tissues and/or organs. Thus, in the present review we highlight the main 3D models involved in TE and PS most used in PDT, as well as the applications, future perspectives and limitations that accompany the techniques aimed at clinical use.

Magnetic and Highly Luminescent Heterostructures of Gd3+/ZnO Conjugated to GCIS/ZnS Quantum Dots for Multimodal Imaging.

In recent years, the use of quantum dots (Qdots) to obtain biological images has attracted attention due to their excellent luminescent properties and the possibility of their association with contrast agents for magnetic resonance imaging (MRI). In this study, Gd3+/ZnO (ZnOGd) were conjugated with Qdots composed of a gadolinium-copper-indium-sulphur core covered with a ZnS shell (GCIS/ZnS Qdots). This conjugation is an innovation that has not yet been described in the literature, and which aims to improve Qdot photoluminescent properties. Structural and morphological Qdots features were obtained by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analyses (TGA). The photoluminescent properties were examined by emission (PL) and excitation (PLE) spectra. A new ZnOGd and GCIS/ZnS (ZnOGd-GCIS/ZnS) nanomaterial was synthesized with tunable optical properties depending on the ratio between the two native Qdots. A hydrophilic or lipophilic coating, using 3-glycidyloxypropyltrimethoxysilane (GPTMS) or hexadecyltrimethoxysilane (HTMS) on the surface of ZnOGd-GCIS/ZnS Qdots, was carried out before assessing their efficiency as magnetic resonance contrast agents. ZnOGd-GCIS/ZnS had excellent luminescence and MRI properties. The new Qdots developed ZnOGd-GCIS/ZnS, mostly constituted of ZnOGd (75%), which had less cytotoxicity when compared to ZnOGd, as well as greater cellular uptake.

Local application of curcumin-loaded nanoparticles as an adjunct to scaling and root planing in periodontitis: Randomized, placebo-controlled, double-blind split-mouth clinical trial.

OBJECTIVE: Assess a single local application of curcumin-loaded nanoparticles as an adjunct to scaling and root planing (SRP) in nonsurgical periodontal treatment (NPT). MATERIALS AND METHODS: Twenty healthy subjects with periodontitis received SRP+PLGA/PLA nanoparticles loaded with 50 µg of curcumin (N-Curc) or SRP+empty nanoparticles. Probing pocket depth (PPD), clinical attachment level (CAL), and bleeding on probing (BOP) were monitored at baseline, 30, 90, and 180 days. IL-1α, IL-6, TNFα, and IL-10 in the gingival crevicular fluid (GCF) were assessed by ELISA, and counts of 40 bacterial species were determined by DNA hybridization at baseline, 3, 7, and 15 days post-therapy. RESULTS: PPD, CAL, and BOP were similarly and significantly improved in both experimental groups. There was no difference in GCF cytokine levels between experimental groups, although IL-6 was decreased at 3 days only in the N-Curc group. NPT reduced counts of red complex bacterial species in both groups. Veillonella Parvula counts increased significantly only in N-Curc group at 7 days, whereas Aggregatibacter actinomycetemcomitans counts increased significantly only in the control group from day 3 to day 15. CONCLUSION: We conclude that a single local administration of nanoencapsulated curcumin in periodontally diseased sites had no additive benefits to NPT. CLINICAL RELEVANCE: Our results showed that a single local application of curcumin-loaded nanoparticles associated with nonsurgical periodontal therapy did not improve clinical outcomes. Hence, our findings do not support the use of curcumin as an adjunct to nonsurgical periodontal therapy.

Photodynamic inactivation of Candida albicans and Candida tropicalis with aluminum phthalocyanine chloride nanoemulsion.

The in vitro susceptibilities of Candida albicans and Candida tropicalis to Antimicrobial Photodynamic Treatment with aluminum phthalocyanine chloride in nanoemulsion (ClAlPc/NE) were investigated. PS concentration- and fluence-dependent cell survival after APDT were compared before and after unbound extracellular PS had been washed out. The PS uptake and its subcellular localization were also determined. Exposure to light in the absence of the PS and treatment with the PS in the absence of light did not kill the fungi. APDT with ClAlPc/NE resulted in a reduction of five orders of magnitude in viability for C. albicans and between four and five orders of magnitude for C. tropicalis. Washing the cells to remove unbound PS before light exposure did not impair fungal inactivation, suggesting that cell photosensitization was mainly carried out by cell bound ClAlPc. The degree of ClAlPc uptake was dependent on its concentration. Internalization of ClAlPc by C. albicans and C. tropicalis was confirmed by confocal fluorescence microscopy that showed the PS does not penetrate the nucleus and instead accumulates in specific regions of the cytoplasm. Our results show that incorporating the water-insoluble ClAlPc into a nanoemulsion leads to an efficient formulation capable of photoinactivating both Candida species.

Sn4+ complexation with sulfonated-carbon dots in pursuit of enhanced fluorescence and singlet oxygen quantum yield.

Here we report a novel strategy to crosslink the surface of sulfonated-carbon dots (S-CDs) by complexing SnCl4 with sulfonate groups (-SO3-) on the CDs in aqueous solution. The S-CDs show an average photoluminescence (PL) quantum yield of 21% and a mean diameter of 3.8 nm. After being complexed with Sn4+, the as-obtained Sn@S-CDs present a reduced size of 1.8 nm and a higher PL quantum yield of 32%. More interestingly, the Sn@S-CDs show an enhanced singlet oxygen (1O2) quantum yield as high as 37% compared to that of the S-CDs (27%). In the HepG2 cell line as a model, the Sn@S-CDs exhibit a remarkable cell imaging effect and in vitro PDT efficiency. Therefore, our study proposes a simple but effective cross-linking strategy to synthesize CDs incorporated with metal ions, for the purpose of achieving an enhanced fluorescence intensity and a higher 1O2 quantum yield.

Antiviral activity of curcumin-nanoemulsion associated with photodynamic therapy in vulvar cell lines transducing different variants of HPV-16.

Vulvar intraepithelial neoplasia (VIN) is associated with human papillomavirus (HPV) infection. Curcumin is a natural bioactive compound with antineoplastic properties. The use of nanoparticles containing curcumin could allow a better performance of this compound in therapies. So, VIN biopsies were collected and HPV DNA detection was performed by PCR, positive samples were genotyped by Restriction Fragment Length Polymorphism (RFLP) and HPV-16 variants were determined by sequencing. HPV-16 positive vulva carcinoma cells (A431) were transduced with E-P and E-350G HPV-16 E6 variants. The viability of the transduced cells treated with nanoemulsions was determined by MTT assay. Besides, apoptosis was evaluated by enzymatic activity of Caspase-3/7. The cell viability assay showed that both the empty nanoemulsion (NE-V) and the nanoemulsion of curcumin (NE-CUR) had little effect on cell viability as compared to control cells. Additionally, we observed that cells irradiated in the presence of NE-CUR presented 90% of cell death. The apoptosis assay further revealed a significant increase in the activity of caspases 3 and 7 in A431 cells expressing both HPV-16 E6 variants after treatment with NE-CUR. Finally, we submitted the HPV transduced A431 cells to organotypic cultures and observed that the combination of treatments affected tissue architecture with evident signals of tissue damage. We concluded that nanoemulsions attain good biocompatibility, since no cytotoxicity was observed and NE-CUR associated with photoactivation showed promising results, leading to death only in cells subjected to irradiation. This drug delivery system associated with photodynamic therapy may become promising in the treatment of vulva lesions.

Copper-Doped Carbon Dots for Optical Bioimaging and Photodynamic Therapy.

Carbon dots (CDs), as an effective bioimaging agent, have aroused widespread interest. With the increasing number of CDs used in photodynamic therapy (PDT), developing efficient CDs with multiple functions such as imaging and phototherapy has become a new challenge. Herein, a new type of copper-doped CDs (Cu-CDs) with a high fluorescence quantum yield of 24.4% was synthesized from a copper complex of poly(acrylic acid) through coordination between the carboxyl group and copper ions. Owing to their good solubility, bright fluorescence, and low cytotoxicity, the Cu-CDs can be used for fluorescence imaging in both the HeLa (human cervical cancer) cell line and SH-SY5Y (human neuroblastoma cells) multicellular spheroids (3D MCs). More importantly, the Cu-CDs show a high quantum yield of singlet oxygen (1O2; 36%), good photoinduced cytotoxicity, and effective inhibition of 3D MC growth. Therefore, the Cu-CDs can be used as a promising imaging-guided PDT agent. This study provides a new carbon-based nanomaterial for multifunctional photodiagnostic and therapeutic agents for biological applications.

Experimental study of the neurotoxic effects of photodynamic therapy on the spinal cord / Estudo experimental dos efeitos neurotóxicos da terapia fotodinâmica na medula espinhal / Estudio experimental de los efectos neurotóxicos de la terapia fotodinámica en la médula espinal

ABSTRACT Objective To evaluate the effects of photodynamic therapy (PDT) on the dura mater using the photosensitizers aluminum chloride phthalocyanine and methylene blue in in vivo assays. Methods Fifty-six male Wistar rats were divided into two groups; one submitted to PDT and the other submitted to the photosensitizers without their photoactivation (control). The photosensitizers were applied to the dura mater after laminectomy at the T10 level. The methods used for assessment were the Basso, Beattie and Bresnahan (BBB) functional evaluation scale and study of the dura mater by light microscopy. Results No changes in motor activity were observed in the animals submitted to PDT compared to control. Histological and pathological evaluation did not show any differences between the group exposed to activated photosensitizers and the control group with regard to the inflammatory process and tissue necrosis. Conclusion The joint use of PDT with the photosensitizing pharmaceuticals aluminum chloride phthalocyanine and methylene blue did not induce any clinical neurotoxic effects or histological changes in the dura mater of the animals studied. Level de evidence V; Expert Opnion.

RESUMO Objetivo Avaliar os efeitos da terapia fotodinâmica (PDT) na dura-máter usando os fotossensibilizadores cloreto de alumínio ftalocianina e azul de metileno em ensaios in vivo. Métodos Cinquenta e seis ratos Wistar machos divididos em dois grupos; um submetido à PDT e o outro submetido aos fotossensibilizadores sem a fotoativação (controle). Os fotossensibilizadores foram aplicados sobre a dura-máter depois de laminectomia no nível T10. Os métodos de avaliação usados foram a escala de avaliação funcional de Basso, Beattie e Bresnahan (BBB) e o estudo da dura-máter por microscopia óptica. Resultados Não foram observadas alterações da atividade motora dos animais submetidos à PDT com relação ao grupo controle. A avaliação histológica e histopatológica não mostrou diferenças entre o grupo exposto aos fotossensibilizadores ativados e o grupo controle, com relação ao processo inflamatório e à necrose tecidual. Conclusões O uso conjunto de PDT e os fármacos fotossensibilizantes cloreto de alumínio ftalocianina e azul de metileno não induziu efeitos neurotóxicos clínicos e/ou alterações histológicas sobre a dura-máter dos animais estudados. Nível de evidência V; Opinião de Especialista.

RESUMEN Objetivo Evaluar los efectos de la terapia fotodinámica (PDT) en la duramadre utilizando los fotosensibilizadores de ftalocianina de aluminio clorada y azul de metileno en ensayos in vivo. Métodos Cincuenta y seis ratas Wistar machos se dividieron en 2 grupos; uno fue sometido a PDT y el otro sometido a fotosensibilizadores sin fotoactivación (control). Los fotosensibilizadores se aplicaron a la duramadre después de la laminectomía en el nivel T10. Los métodos de evaluación utilizados fueron la escala de evaluación funcional de Basso, Beattie y Bresnahan (BBB) y el estudio de la duramadre mediante microscopía óptica. Resultados No hubo cambios en la actividad motora de los animales sometidos a PDT en relación con el grupo de control. La evaluación histológica e histopatológica no mostró diferencias entre el grupo expuesto a fotosensibilizadores activados y el grupo de control con respecto al proceso inflamatorio y la necrosis tisular. Conclusiones El uso conjunto de PDT con las sustancias fotosensibilizadores ftalocianina de aluminio clorada y azul de metileno no indujo efectos neurotóxicos clínicos o cambios histológicos en la duramadre de los animales estudiados. Nivel de evidencia V; Opinión del Especialista.

Effect of curcumin-nanoemulsion associated with photodynamic therapy in breast adenocarcinoma cell line.

Curcumin, a natural compound has several antineoplastic activities and is a promising natural photosensitizer used in photodynamic therapy. However, its low solubility in physiological medium limit the clinical use of curcumin. This study aimed to analyze the action of curcumin-nanoemulsion, a new and well-designed Drug Delivery System (DDS+) molecule, used as a photosensitizing agent in photodynamic therapy in an in vitro breast cancer model, MCF-7 cells. The empty nanoemulsion fulfils all necessary requirements to be an excellent DDS. Furthermore, the use of curcumin-nanoemulsion in photodynamic therapy resulted in a high phototoxic effect after activation at 440 nm, decreasing to <10% viable tumor cells after two irradiations and increasing the reactive oxygen species (ROS) production. The use of curcumin-nanoemulsion associated with photodynamic therapy resulted in an increase in the levels of caspase 3/7 activity for the studied MCF-7 cell model, indicating that this therapy triggers a cascade of events that lead to cell death, such as cellular apoptosis. In conclusion, curcumin-nanoemulsion proved to be efficient as a photosensitizing agent, had phototoxic effects, significantly decreased the proliferation of MCF-7 cells and stimulating the ROS production in combination with photodynamic therapy, so, this formulation has a great potential for use in treatment of breast cancer.

Synthesis and colloidal characterization of folic acid-modified PEG-b-PCL Micelles for methotrexate delivery.

Hydrophobic drugs, such as methotrexate, are not easily delivered into the human body. Therefore, the use of amphiphilic nanoplatforms to the transport of these drugs through the bloodstream is a challenge. While the hydrophobic region interacts with the drug, the hydrophilic outer layer enhances its bioavailability and circulation time. Poly (ethylene glycol)-block-poly(ε-caprolactone) PEG-b-PCL micelles are biodegradable and biocompatible, allowing its use as a nanocarrier for drug delivery systems. The stealth property of PEG that composes the outer layer of nanoplatforms, makes the micelle unperceivable to phagocytic cells, increasing the circulation time in the human body. In addition, folic acid functionalization enables micelle selectively targeting to cancer cells, improving treatment efficiency and reducing side effects. In this work, PEG-b-PCL copolymer was synthesized by ring opening polymerization (ROP) of the ε-caprolactone with Poly(ethylene glycol) as a macroinitiator and tin(II) 2-ethyl hexanoate as a catalyst. Functionalization of such micelles with folic acid occurred through the modification of the PEG terminal group. The surface modification of the copolymer micelles resulted in higher critical micellar concentration (CMC), increasing approximately 100 times. The synthesis of the copolymers resulted in molecular weight around 3000 g mol-1 with low polydispersity. The polymer micelles have a hydrodynamic diameter in the range of 100-200 nm and the functionalized sample doesn't show aggregation in the considered pH range. High incorporation efficiency was obtained with a minimum percentage of 85%. The drug release profile and linearization from the Peppas model confirmed the interaction of methotrexate with the hydrophobic segment of the copolymer and its release mechanism by relaxation and/or degradation of the chains, making PEG-b-PCL micelles suitable candidates for hydrophobic drug delivery systems.

Combining Photodynamic Therapy and Chemotherapy: Improving Breast Cancer Treatment with Nanotechnology.

Nanomedical approaches are the major transforming factor in cancer therapies. Based on important previous works in the field of drug delivery nanomaterials, recent years have brought a broad array of new and improved intelligent nanoscale platforms that are suited to deliver drugs. In this context, the purpose of this study was to investigate the action of different nanoemulsions designed to encapsulate chloroaluminum phthalocyanine, a hydrophobic photosensitizer used in photodynamic therapy, and doxorubicin, a well-known chemotherapeutic agent used to treat aggressive breast cancer cells. The mean nanostructured system size ranged from 170.8 to 181.0 nm, and the nanoemulsions presented spherical morphology. All formulations exhibited negative zeta potential values (-68.7 to -75.0 mV) and suitable polydispersity values (0.20 to 0.28), explaining their colloidal stability up to three months. Murine breast cancer cells (4T1) were incubated with nanoemulsions for three hours at various concentrations and were subjected to cell viability tests to find the concentration dependence profile. Thereafter, the in vitro phototoxic effect was evaluated in the presence of the visible laser light irradiation. Less than 10% of 4T1 viable cells were observed when photodynamic therapy and chemotherapy were combined at a 1.0 J · cm-2 laser light dose with 1.0 µM phthalocyanine and 0.5 µM doxorubicin. The cell death assay and cell cycle arrest analysis confirmed the therapy efficiency demonstrating an increase in the apoptosis rate and in the cell cycle arrest on G2. Additionally, 15 genes related to apoptosis and 25 target genes of anti-cancer drugs were overexpressed. Four genes related to apoptosis and four target genes of anti-cancer drugs were downregulated in 4T1 cells after treatment with nanoemulsion with phthalocyanine and doxorubicin associated with photodynamic therapy. Thus, the nanoemulsions loaded with phthalocyanine and doxorubicin presented appropriate physical stability, improved photophysical properties, and remarkable activity in vitro to be considered as promising formulations for photodynamic therapy and chemotherapeutic use in breast cancer treatment.

Effect of Curcumin-Nanoemulsion Associated with Photodynamic Therapy in Cervical Carcinoma Cell Lines.

Cervical cancer is the fourth cause of cancer death in women. Curcumin has antineoplastic properties. Furthermore, curcumin may be used as a photosensitizing agent in Photodynamic Therapy. This study aimed to investigate the effects of Photodynamic Therapy in cellular viability using curcumin-nanoemulsion as a photosensitizing drug in cervical carcinoma cell lines. The empty nanoemulsion presented very low cytotoxicity in all cell lines analyzed. Additionally, the incubation with curcumin-nanoemulsion at 20 µM of curcumin showed more than 80% of cell viability for cell lines. Nanoemulsions were shown to be internalized inside cells by fluorescence microscopy and were observed in the intracellular environment for up to 36 hours after incubation with cell lines. In addition, after the Photodynamic Therapy we observed a high phototoxic effect of the curcumin-nanoemulsion with less than 5% of viable cells after irradiation. This was accompanied by an increase in caspase-3/caspase-7 activities after cell treatment with curcumin-nanoemulsion and Photodynamic Therapy, suggesting cell death by apoptosis. We conclude that the curcumin-nanoemulsion formulation behaves as a photosensitizing drug in Photodynamic Therapy and shows potential as an alternative treatment to cervical lesions using an endoscopic diode fiber laser setup for in situ activation or cavity activation using a diffuse fiber delivery system.

In vitro assessment of anti-tumorigenic mechanisms and efficacy of NanoALA, a nanoformulation of aminolevulic acid designed for photodynamic therapy of cancer.

BACKGROUND: The development of nanocarriers is an important approach to increase the bioavailability of hydrophilic drugs in target cells. In this work, we evaluated the anti-tumorigenic mechanisms and efficacy of NanoALA, a novel nanoformulation of aminolevulic acid (ALA) based on poly(lactide-co-glycolide) (PLGA) nanocapsules designed for anticancer photodynamic therapy (PDT). METHODS: For this purpose, physicochemical characterization, prodrug incorporation kinetics, biocompatibility and photocytotoxicity tests, analysis of the cell death type and mitochondrial function, measurement of the intracellular reactive oxygen species production and DNA fragmentation were performed in murine mammary carcinoma (4T1) cells. RESULTS: NanoALA formulation, stable over a period of 90days following synthesis, presented hydrodynamic diameter of 220±8.7nm, zeta potential of -30.6mV and low value of polydispersity index (0.28). The biological assays indicated that the nanostructured product promotes greater ALA uptake by 4T1 cells and consequently more cytotoxicity in the PDT process. For the first time in the scientific literature, there is a therapeutic efficacy report of approximately 80%, after only 1h of incubation with 100µgmL-1 prodrug (0.6mM ALA equivalent). The mitochondria are probably the initial target of treatment, culminating in energy metabolism disorders and cell death by apoptosis. CONCLUSIONS: NanoALA emerges as a promising strategy for anticancer PDT. Besides being effective against a highly aggressive tumor cell line, the treatment may be economically advantageous because it allows a reduction in the dose and frequency of application compared to free ALA.

Collagen-based silver nanoparticles: Study on cell viability, skin permeation, and swelling inhibition.

Collagen is considered the most abundant protein in the animal kingdom, comprising 30% of the total amount of proteins and 6% of the human body by weight. Studies that examine the interaction between silver nanoparticles and proteins have been highlighted in the literature in order to understand the stability of the nanoparticle system, the effects observed in biological systems, and the appearance of new chemical pharmaceutical products. The objective of this study was to analyze the behavior of silver nanoparticles stabilized with collagen (AgNPcol) and to check the skin permeation capacity and action in paw edema induced by carrageenan. AgNPcol synthesis was carried out using solutions of reducing agent sodium borohydride (NaBH4), silver nitrate (AgNO3) and collagen. Characterization was done by using dynamic light scattering (DLS) and X-ray diffraction (XRD) and AFM. Cellular viability testing was performed by using flow cytometry in human melanoma cancer (MV3) and murine fibroblast (L929) cells. The skin permeation study was conducted using a Franz diffusion cell, and the efficiency of AgNPcol against the formation of paw edema in mice was evaluated. The hydrodynamic diameter and zeta potential of AgNPcol were 140.7±7.8nm and 20.1±0.7mV, respectively. AgNPcol failed to induce early apoptosis, late apoptosis, and necrosis in L929 cells; however, it exhibited enhanced toxicity in cancer cells (MV3) compared to normal cells (L929). AgNPcol demonstrated increased toxicological effects in cancer MV3 cells, promoting skin permeation, and preventing paw edema.

Acetylated cashew gum-based nanoparticles for transdermal delivery of diclofenac diethyl amine.

Nanoprecipitation and dialysis methods were employed to obtain nanoparticles (NPs) of acetylated cashew gum (ACG). NPs synthesized by dialysis showed greater average size compared to those synthesized by nanoprecipitation, but they presented improved stability and yield. NPs were loaded with diclofenac diethylamine and the efficiency of the drug incorporation was over 60% for both methods, for an ACG:NP a weight ratio of 10:1. The cytotoxicity assay demonstrated that the NPs had no significant effect on the cell viability, verifying their biocompatibility. The release profile for the diclofenac diethylamine associated with the ACG-NPs showed a more controlled release compared to the free drug and a Fickian diffusion mechanism was observed. Transdermal permeation reached 90% penetration of the drug.