Carbon nanotubes (CNTs) are nanomaterials with multiple possible uses as drug carriers or in nanovaccine development. However, the toxicity of CNTs administered intravenously in in vivo models has not been fully described to date. This work aimed to evaluate the toxic effect of pristine multi-walled CNTs (UP-CNTs), purified (P-CNTs), or CNTs functionalized with fluorescein isothiocyanate (FITC-CNTs) administered by intravenous injection in BALB/c mice. Biochemical and histopathological parameters were analyzed at 1, 14, 29, and 60 days post-exposure. Pristine CNTs were the most toxic nanoparticles in comparison with P-CNTs or FITC-CNTs, increasing serum AST (≈ 180%), ALT (≈ 300%), and LDH (≈ 200%) levels at one day post-exposure. The urea/creatinine ratio suggested pre-renal injury at the 14th day accompanied of extensive lesions in kidneys, lungs, and liver. Biochemical and histological findings in mice exposed to P-CNTs had not significant differences compared to the controls. A lower toxic effect was detected in animals exposed to FITC-CNTs which was attributable to FITC toxicity. These results demonstrate that the purification process of CNTs reduces in vivo toxicity, and that toxicity in functionalized CNTs is dependent on the functionalized compound. Therefore, P-CNTs are postulated as potential candidates for safe biomedical applications using an intravenous pathway.

Carbon nanotubes (CNTs) have been proposed as nanovehicles for drug or antigen delivery since they can be functionalized with different biomolecules. For this purpose, different types of molecules have been chemically bonded to CNTs; however, this method has low efficiency and generates solvent waste. Candida antarctica lipase is an enzyme that, in an organic solvent, can bind a carboxylic to a hydroxyl group by esterase activity. The objective of this work was to functionalize purified CNTs with insulin as a protein model using an immobilized lipase of Candida antarctica to develop a sustainable functionalization method with high protein attachment. The functionalized CNTs were characterized by scanning electron microscope (SEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE). The enzymatic functionalization of insulin on the surface of the CNTs was found to have an efficiency of 21%, which is higher in conversion and greener than previously reported by the diimide-activated amidation method. These results suggest that enzymatic esterification is a convenient and efficient method for CNT functionalization with proteins. Moreover, this functionalization method can be used to enhance the cellular-specific release of proteins by lysosomal esterases.

Novel lipid-based nanosystems have been of interest in improving conventional drug release methods. Liposomes are the most studied nanostructures, consisting of lipid bilayers ideal for drug delivery, thanks to their resemblance to the cell plasma membrane. Asymmetric liposomes are vesicles with different lipids in their inner and outer layers; because of this, they can be configured to be compatible with the therapeutic drug while achieving biocompatibility and stability. Throughout this review, topics such as the applications, advantages, and synthesis techniques of asymmetric liposomes will be discussed. Further, an in silico analysis by computational tools will be examined as a helpful tool for designing and understanding asymmetric liposome mechanisms in pharmaceutical applications. The dual-engineered design of asymmetric liposomes makes them an ideal alternative for transdermal drug delivery because of the improved protection of pharmaceuticals without lowering adsorption rates and system biocompatibility.

Background/Objectives: Second-degree burns require strategies that address microbial contamination, oxidative stress, exudate, and tissue repair. This study aimed to develop and evaluate a marine-derived chitosan hydrogel incorporating ethanolic extract of propolis (EEP) from Chihuahua, Mexico, for second-degree burn management. Methods: EEP was characterized using parameters established in NOM-003-SAG/GAN-2017 and complementary biological assays. Chitosan hydrogels containing 1%, 3%, and 5% (w/w) EEP were evaluated for physicochemical properties, swelling, mass loss, flavonoid release, antioxidant activity, antimicrobial performance, and cell viability. The 1% EEP hydrogel was further evaluated in a murine second-degree burn model. Results: Chihuahua propolis exhibited high phenolic (27.42 ± 2.53%) and flavonoid (9.23 ± 0.314%) contents. EEP incorporation modified the chitosan matrix, providing high swelling capacity, increased structural persistence, sustained flavonoid release for 72 h, and radical-scavenging activity for 96 h. Antimicrobial activity was concentration-dependent, with the 5% EEP hydrogel reducing recoverable Escherichia coli counts below the detection limit (<10² CFU/mL). However, EEP-containing hydrogels reduced NIH-3T3 viability below the 70% ISO 10993-5 threshold under static extraction conditions. At 144 h, the 1% EEP hydrogel produced greater wound contraction than silver sulfadiazine (p = 0.021), although it did not differ significantly from the propolis-free chitosan hydrogel or untreated control. Qualitative histological assessment showed features consistent with early tissue repair, with cutaneous appendages observed in several sections from the 1% EEP group. Conclusions: Chihuahua propolis-loaded chitosan hydrogels showed promising physico-chemical, release, antioxidant, antimicrobial, and short-term in vivo findings. The in vitro reduction in metabolic activity observed under static extraction conditions warrants further evaluation using physiologically relevant exposure models, extended follow-up, and comprehensive safety assessment.