Zinc-Based Nanoparticles Reduce the Bacterial Burden and Protect Collagen in a Mouse Cutaneous Wound Model Rafael Bianchini Fulindi, Thúlio Wliandon Lemos Barbosa, Vanessa Enriquez, Claudia Charles‐Niño, Natália Galvão de Freitas, et al. ACS Omega, 2026 ), suggesting specific interference in biofilm formation pathways. Topical treatment of skin wound infection in Balb/c mice led to a significant reduction in bacterial burden. Notably, while Zn-NPs did not promote initial wound healing, they inhibited the degradation of collagen by bacteria and/or helped maintain collagen levels in the skin of the mice. These findings demonstrate that Zn-NPs effectively reduce early bacterial burden in mouse skin wounds while preserving cutaneous tissue collagen integrity, establishing their dual therapeutic potential as both antimicrobial and tissue-protective agents in wound management.
Bimodal Poly(lactic-co-glycolic acid) Nanocarrier with Zinc Oxide and Iron Oxide for Fluorescence and Magnetic Resonance Imaging Thúlio Wliandon Lemos Barbosa, Laurent Lemaire, Isabelle Verdu, Larissa Santos, Natália Galvão de Freitas, Mariana Picchi Salto, Leila Aparecida Chiavacci Molecules, 2025 Zinc oxide (ZnO) and iron oxide (IO) nanoparticles have been identified as promising candidates for biomedical applications, based on their unique physicochemical properties. The association of these nanoparticles in a single system creates a bimodal entity, allowing the excellent luminescent properties of ZnO quantum dots to be combined with the contrast agent of IO for magnetic resonance imaging (MRI). The present study focuses on the luminescent and MRI properties of a new poly(lactic-co-glycolic acid) (PLGA) nanocarrier system formulation containing ZnO NPs and IO NPs in different nominal ratios. Microscopic analysis (TEM and SEM) reveals a circular morphology with IO and ZnO NPs. The average diameter of the particles was determined to be 220 nm, as measured by DLS. The luminescence results indicate that the PLGA system shows strong emission in the visible range, and the MRI analysis shows a high r2 relaxivity of 171 mM−1 s−1 at 7T. The optimized formulation, exhibiting a molar ratio of Fe:Zn ranging from 1:10 to 1:13 (mol:mol), demonstrates superior fluorescence and MRI performance, underscoring the significance of nanoparticle composition in bimodal imaging applications. The systems evaluated demonstrate no toxicity in the THP-1 cells for doses of up to 128 µg mL−1, with efficient labeling after 4 h of incubation, yielding images of strong luminescence and T2 contrast. The PLGA:ZnO:IO system demonstrates considerable potential as a bimodal platform for diagnostic imaging.
Hybrid Membranes of the Ureasil-Polyether Containing Glucose for Future Application in Bone Regeneration Camila Garcia da Silva, João Rodrigues Monteiro, João Augusto Oshiro-Júnior, Leila Aparecida Chiavacci Pharmaceutics, 2023 The application of mesenchymal stem cells (MSC) in bone tissue regeneration can have unpredictable results due to the low survival of cells in the process since the lack of oxygen and nutrients promotes metabolic stress. Therefore, in this work, polymeric membranes formed by organic–inorganic hybrid materials called ureasil-polyether for modified glucose release were developed in order to overcome the problems posed by a of lack of this nutrient. Thus, membranes formed by polymeric blend of polypropylene oxide (PPO4000) and polyethylene oxide (PEO500) with 6% glucose incorporation were developed. Physical–chemical characterization techniques were performed, as well as tests that evaluated thermal properties, bioactivity, swelling, and release in SBF solution. The results of the swelling test showed an increase in membrane mass correlated with an increase in the concentration of ureasil-PEO500 in the polymeric blends. The membranes showed adequate resistance when subjected to the application of a high compression force (15 N). X-ray diffraction (XRD) evidenced peaks corresponding to orthorhombic crystalline organization, but the absence of glucose-related peaks showed characteristics of the amorphous regions of hybrid materials, likely due to solubilization. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analyses showed that the thermal events attributed to glucose and hybrid materials were similar to that seen in the literature, however when glucose was incorporated into the PEO500, an increase in rigidity occurs. In PPO400, and in the blends of both materials, there was a slight decrease in Tg values. The smaller contact angle for the ureasil-PEO500 membrane revealed the more hydrophilic character of the material compared to other membranes. The membranes showed bioactivity and hemocompatibility in vitro. The in vitro release test revealed that it is possible to control the release rate of glucose and the kinetic analysis revealed a release mechanism characteristic of anomalous transport kinetics. Thus, we can conclude that ureasil-polyether membranes have great potential to be used as a glucose release system, and their future application has the potential to optimize the bone regeneration process.
Zinc-Based Nanoparticles Reduce Bacterial Biofilm Formation Rafael Bianchini Fulindi, Juliana Domingues Rodrigues, Thulio Wliandon Lemos Barbosa, Ariana D. Goncalves Garcia, Felipe de Almeida La Porta, Sebastião Pratavieira, Leila Aparecida Chiavacci, João Pessoa Araújo Junior, Paulo Inácio da Costa, Luis R. Martinez Microbiology Spectrum, 2023 Zinc (Zn)-based nanoparticles (NPs) can be potentially used in medical and food preservation applications. As proof of principle, we investigated the bactericidal and antibiofilm activity of zinc oxide (ZnO) and zinc sulfide (ZnS) NPs against medically important bacteria.
Zinc-Based Nanoparticles Reduce Bacterial Biofilm Formation Rafael Bianchini Fulindi, Juliana Domingues Rodrigues, Thulio Wliandon Lemos Barbosa, Ariana D. Goncalves Garcia, Felipe de Almeida La Porta, Sebastião Pratavieira, Leila Aparecida Chiavacci, João Pessoa Araújo Junior, Paulo Inácio da Costa, Luis R. Martinez Microbiology Spectrum, 2023 Zinc (Zn)-based nanoparticles (NPs) can be potentially used in medical and food preservation applications. As proof of principle, we investigated the bactericidal and antibiofilm activity of zinc oxide (ZnO) and zinc sulfide (ZnS) NPs against medically important bacteria.
Dexamethasone Acetate Nanocrystals, Characterization and Dissolution Studies in Presence of Polymorphic Phases Thúlio Wliandon Lemos Barbosa, Flavia Lemos Ayres da Gama Bastos, Bruna Lallo da Silva, João Augusto Oshiro Junior, Leila Aparecida Chiavacci Pharmaceutical Nanotechnology, 2023 Background: A drug with poor water-solubility, like Dexamethasone acetate, can present lower bioavailability conventional for pharmaceutical formulations, and the presence of polymorphs in the raw material can lead to drug quality problems. Objective: In this study, nanocrystals of dexamethasone acetate were synthesized by high pressure homogenizer (HPH) method in surfactant poloxamer 188 (P188) solid dispersion and the bioavailable in raw material with polymorphism presence was evaluated. Methods: The powder pre-suspension was prepared by the HPH process, and the nanoparticles formed were incorporated in P188 solutions. The nanocrystals formed were characterized by techniques of XRD, SEM, FTIR, thermal analysis by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), dynamic light scattering (DLS) to analyze the particle size and zeta potential, and in vitro evaluation by dissolution studies. Results: The characterization techniques were adequate to show the presence of raw material with physical moisture between two dexamethasone acetate polymorphs. The nanocrystals formed in the presence of the P188 in the formulation showed a considerable increase in the rate of dissolution of the drug in the medium and in the size of the stable nanocrystals, even in the presence of dexamethasone acetate polymorphs. Conclusion: The results showed that it was possible to produce dexamethasone nanocrystals by HPH process with regular size by the presence of the small amount of P188 surfactant. This article presents a novelty in the development of dexamethasone nanoparticles that have different polymorphic forms in their physical composition.
ZnO@ZIF-8 Nanoparticles as Nanocarrier of Ciprofloxacin for Antimicrobial Activity Bruno Altran Costa, Marina Paiva Abuçafy, Thúlio Wliandon Lemos Barbosa, Bruna Lallo da Silva, Rafael Bianchini Fulindi, Guilherme Isquibola, Paulo Inácio da Costa, Leila Aparecida Chiavacci Pharmaceutics, 2023 Numerous antimicrobial drugs have been prescribed to kill or inhibit the growth of microbes such as bacteria, fungi, and viruses. Despite the known therapeutic efficacy of these drugs, inefficient delivery could result in an inadequate therapeutic index and several side effects. In order to overcome this adversity, the present study investigated antibiotic drug loading in zeolitic imidazolate frameworks (ZIFs), in association with ZnO nanoparticles with known antimicrobial properties. In an economic synthesis method, the ZnO surface was first converted to ZIF-8 with 2-methylimidazole as a ligand, resulting in a ZnO@ZIF-8 structure. This system enables the high drug-loading efficiency (46%) of an antimicrobial drug, ciprofloxacin, within the pores of the ZIF-8. This association provides a control of the release of the active moieties, in simulated body-fluid conditions, with a maximum of 67% released in 96 h. The antibacterial activities of ZnO@ZIF-8 and CIP-ZnO@ZIF-8 were tested against the Gram-positive Staphylococcus aureus strain and the Gram-negative Pseudomonas aeruginosa strain, showing good growth inhibition. This result was obtained by combining ZnO@ZIF-8 with ciprofloxacin in a minimal inhibitory concentration (MIC) that was 10 times lower than ZnO@ZIF-8 for S. aureus and 200 times lower for P. aeruginosa, suggesting that CIP-ZnO@ZIF-8 may have potential application in prolonged antimicrobial treatment.
MIL-100(Fe) Sub-Micrometric Capsules as a Dual Drug Delivery System Marina Paiva Abuçafy, Regina Celia Galvao Frem, Giulia Polinario, Fernando Rogerio Pavan, Heng Zhao, Angelika Mielcarek, Cedric Boissiere, Christian Serre, Leila Aparecida Chiavacci International Journal of Molecular Sciences, 2022
Dexamethasone-Loaded Ureasil Hydrophobic Membrane for Bone Guided Regeneration Rafaella Moreno Barros, Camila Garcia Da Silva, Kammila Martins Nicolau Costa, Arnóbio A. Da Silva-Junior, Cássio Rocha Scardueli, Rosemary Adriana Chiérici Marcantonio, Leila Aparecida Chiavacci, João Augusto Oshiro-Junior Pharmaceutics, 2022
In vivo effectiveness of hybrid membranes with osteogenic growth peptide for bone regeneration João Augusto Oshiro‐Junior, Rafaela Moreno Barros, Camila Garcia Silva, Caroline Cordeiro Souza, Cássio Rocha Scardueli, Camila Chiérici Marcantonio, Paulo Ricardo Silva Saches, Larissa Mendes, Eduardo Maffud Cilli, Rosemary Adriana Chierici Marcantonio, Leila Aparecida Chiavacci Journal of Tissue Engineering and Regenerative Medicine, 2021
Nanoparticles for cosmetic use and its application Bruna Galdorfini Chiari-Andréo, Maria Gabriela José de Almeida-Cincotto, João Augusto Oshiro, Cibele Yumi Yamada Taniguchi, Leila Aparecida Chiavacci, Vera Lucia Borges Isaac Nanoparticles in Pharmacotherapy, 2019
Physicochemical characterization of drug nanocarriers Eloísa Berbel Manaia, Marina Paiva Abuçafy, Bruna Galdorfini Chiari-Andréo, Bruna Lallo Silva, João Augusto Oshiro-Júnior, Leila Chiavacci International Journal of Nanomedicine, 2017
The influence of nanoparticle size on the antibacterial activity of ZnO Revista De Ciencias Farmaceuticas Basica E Aplicada, 2017
Evaluation of the encapsulation efficiency and monitoring of the in vitro release profile of metal organic frameworks (MOFs) Revista De Ciencias Farmaceuticas Basica E Aplicada, 2017
