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Conventional cancer therapies suffer from nonspecificity, drug resistance, and a poor bioavailability, which trigger severe side effects. To overcome these disadvantages, in this study, we designed and evaluated the in vitro potential of paclitaxel-loaded, PLGA-gold, half-shell nanoparticles (PTX-PLGA/Au-HS NPs) conjugated with cyclo(Arg-Gly-Asp-Phe-Lys) (cyRGDfk) as a targeted chemo-photothermal therapy system in HeLa and MDA-MB-231 cancer cells. A TEM analysis confirmed the successful gold half-shell structure formation. High-performance liquid chromatography showed an encapsulation efficiency of the paclitaxel inside nanoparticles of more than 90%. In the release study, an initial burst release of about 20% in the first 24 h was observed, followed by a sustained drug release for a period as long as 10 days, reaching values of about 92% and 49% for NPs with and without near infrared laser irradiation. In in vitro cell internalization studies, targeted nanoparticles showed a higher accumulation than nontargeted nanoparticles, possibly through a specific interaction of the cyRGDfk with their homologous receptors, the ανß3 y ανß5 integrins on the cell surface. Compared with chemotherapy or photothermal treatment alone, the combined treatment demonstrated a synergistic effect, reducing the cell viability to 23% for the HeLa cells and 31% for the MDA-MB-231 cells. Thus, our results indicate that these multifuncional nanoparticles can be considered to be a promising targeted chemo-photothermal therapy system against cancer.

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The versatile combination of metal nanoparticles with chemotherapy agents makes designing multifunctional drug delivery systems attractive. In this work, we reported cisplatin's encapsulation and release profile using a mesoporous silica-coated gold nanorods system. Gold nanorods were synthesized by an acidic seed-mediated method in the presence of cetyltrimethylammonium bromide surfactant, and the silica-coated state was obtained by modified Stöber method. The silica shell was modified first with 3-aminopropyltriethoxysilane and then with succinic anhydride to obtain carboxylates groups to improve cisplatin encapsulation. Gold nanorods with an aspect ratio of 3.2 and silica shell thickness of 14.74 nm were obtained, and infrared spectroscopy and ζ potential studies corroborated surface modification with carboxylates groups. On the other hand, cisplatin was encapsulated under optimal conditions with an efficiency of ~58%, and it was released in a controlled manner over 96 h. Furthermore, acidic pH promoted a faster release of 72% cisplatin encapsulated compared to 51% in neutral pH.

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Pseudomonas aeruginosa infections have become more challenging to treat and eradicate due to their ability to form biofilms. This study aimed to produce hydrophobic nanoparticles by grafting 11-carbon and three-carbon alkyl chains to a chitosan polymer as a platform to carry and deliver carvacrol for improving its antibacterial and antibiofilm properties. Carvacrol-chitosan nanoparticles showed ζ potential values of 10.5-14.4 mV, a size of 140.3-166.6 nm, and an encapsulation efficiency of 25.1-68.8%. Hydrophobic nanoparticles reduced 46-53% of the biomass and viable cells (7-25%) within P. aeruginosa biofilms. Diffusion of nanoparticles through the bacterial biofilm showed a higher penetration of nanoparticles created with 11-carbon chain chitosan than those formulated with unmodified chitosan. The interaction of nanoparticles with a 50:50 w/w phospholipid mixture at the air-water interface was studied, and values suggested that viscoelasticity and fluidity properties were modified. The modified nanoparticles significantly reduced viable P. aeruginosa in biofilms (0.078-2.0 log CFU·cm-2) and swarming motility (40-60%). Furthermore, the formulated nanoparticles reduced the quorum sensing in Chromobacterium violaceum. This study revealed that modifying the chitosan polarity to synthesize more hydrophobic nanoparticles could be an effective treatment against P. aeruginosa biofilms to decrease its virulence and pathogenicity, mainly by increasing their ability to interact with the membrane phospholipids and penetrate preformed biofilms.

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Bacterial infections have become one of the top ten public health concerns worldwide. These problems are aggravated with the emergence of multi-drug resistant bacterial strains. Thus, it is necessary to adopt novel technological strategies, such as development of bionanomaterials to prevent the infection, and treat this kind of bacteria. At this regard, the chemical modification of chitosan (Cs), by the covalent attachment of a hydrocarbon chain (octanoic acid), was developed to obtain hydrophobic chitosan (HCs). Then, HCs was used to synthetize nanoparticles using the well-known ionotropic gelation approach, optimizing the parameters, such as the TPP/HCs ratio and pH solution to get stable nanoparticles. Then, carvacrol (CAR) was loaded into NPs (HCs-CAR NPs) using different concentrations of 25%, 50% and 75% (%w/w CAR/HCs). The physicochemical properties for HCs-CAR NPs prepared at 50% of CAR stood out from the rest, showing a spherical morphology, with a size of 200 nm, Z potential of 10.4 mV and encapsulation efficiency of 56.28%. These formulations were chosen to evaluate the antibacterial activity, using Gram-negative (Escherichia coli) and Gram-positive bacterial model (Staphylococcus aureus). The HCs-CAR NPs showed great activity against both bacterial models, being more effective against Gram (+) strain (S. aureus), suggesting the potential application of these NPs as novel biomaterial to treat bacterial infection.

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In this study, allyl-isothiocyanate (AITC)-loaded Polylactic-Co-Glycolic Acid (PLGA) Nanoparticles (NPs) were prepared for targeting epithelial squamous carcinoma cells using a specific antibody targeting the Epidermal Growth Factor (EGF) receptor overexpressed on the cell membranes. AITC-loaded PLGA NPs showed more effective anticancer properties compared with free AITC, and their cytotoxicity was even more pronounced when the anti-EGFR antibody was covalently attached to the NPs surface. This targeting ability was additionally tested by co-culturing cervical HeLa cells, with very few EGFR on the membranes, and epithelial squamous carcinoma A431 cells, which largely overexpressed EFGR, being observed the specific localization of the antibody-functionalized AITC-loaded PLGA NPs solely in the latter types of cells, whereas non-functionalized NPs were distributed randomly in both cell types in much lesser extents. Thus, our findings support the development of drug delivery strategies that enhances the delivery of anti-cancer natural compounds to tumor tissue, in this case, by targeting specific tumor cell receptors with cell-specific ligands followed by tumor sensitization.

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Hybrid nanoparticles containing both structural and functional nanocomponents might result in higher success and increased quality of life for patients suffering a disease such as cancer. In this study, we combine chemotherapy of conventional drug doxorubicin (Dox) with gold nanorods (AuNR) for photothermal therapy using multifunctional human serum albumin nanoparticles (HSA NP's) fabricated via desolvation technique with high efficiency. Folic acid (FA) was conjugated to HSA NP's trough an amidation via carbodiimide reaction for a more specific nanoplataform to HeLa cancer cells. The loading efficiency of Dox into AuNR loaded-HSA NP reached up to 2 µg Dox/mg HSA. The HSA-AuNR-Dox NP experienced photothermal heating varying laser potency (1, 0.5 and 0.2 W); reaching the bulk particle solution an increment of 16, 8 and 6 °C after 10 min of near-IR laser exposure respectively. When HeLa cells were treated with this multifunctional nanoplataform containing only AuNR, cancer cells experienced 96% cell viability without irradiation and 55% cell viability after just one irradiation session. When Dox is present in the nanoplataform, viability were 60% and 24% for non-irradiated and irradiated nanoplataforms, respectively. This study demonstrates that HSA-AuNR-Dox nanoparticles are suitable systems allowing a synergic chemo and phothothermal therapy.

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