Understanding mucus modulation behavior of chitosan oligomers and dextran sulfate combining light scattering and calorimetric observations.

This study reports the fundamental understanding of mucus-modulatory strategies combining charged biopolymers with distinct molecular weights and surface charges. Here, key biophysical evidence supports that low-molecular-weight (Mw) polycation chitosan oligosaccharides (COSs) and high-Mw polyanion dextran sulfate (DS) exhibit distinct thermodynamic signatures upon interaction with mucin (MUC), the main protein of mucus. While the COS â†’ MUC microcalorimetric titrations released ~14 kcal/mol and ~60 kcal/mol, the DS â†’ MUC titrations released ~1200 and ~1450 kcal/mol at pH of 4.5 and 6.8, respectively. The MPT-2 titrations of COS â†’ MUC and DS â†’ MUC indicated a greater zeta potential variation at pH = 4.5 (relative variation = 815 % and 351 %, respectively) than at pH = 6.8 (relative variation = 282 % and 136 %, respectively). Further, the resultant binary (COS-MUC) and ternary (COS-DS-MUC) complexes showed opposite behavior (aggregation and charge inversion events) according to the pH environment. Most importantly, the results indicate that electrostatics could not be the driving force that governs COS-MUC interactions. To account for this finding, we proposed a two-level abstraction model. Macro features emerge collectively from individual interactions occurring at the molecular level. Therefore, to understand the outcomes of mucus modulatory strategy based on charged biopolymers it is necessary to integrate both visions into the same picture.

Immunomodulatory properties of nanostructured systems for cancer therapy.

Based on statistical data reported in 2020, cancer was responsible for approximately 10 million deaths. Furthermore, 17 million new cases were diagnosed worldwide. Nanomedicine and immunotherapy have shown satisfactory clinical results among all scientific and technological alternatives for the treatment of cancer patients. Immunotherapy-based treatments comprise the consideration of new alternatives to hinder neoplastic proliferation and to reduce adverse events in the body, thereby promoting immune destruction of diseased cells. Additionally, nanostructured systems have been proven to elicit specific immune responses that may enhance anti-tumor activity. A new generation of nanomedicines, based on biomimetic and bioinspired systems, has been proposed to target tumors by providing immunomodulatory features and by enabling recovery of human immune destruction capacity against cancer cells. This review provides an overview of the aspects and the mechanisms by which nanomedicines can be used to enhance clinical procedures using the immune modulatory responses of nanoparticles (NPs) in the host defense system. We initially outline the cancer statistics for conventional and new treatment approaches providing a brief description of the human host defense system and basic principles of NP interactions with monocytes, leukocytes, and dendritic cells for the modulation of antitumor immune responses. A report on different biomimetic and bioinspired systems is also presented here and their particularities in cancer treatments are addressed, highlighting their immunomodulatory properties. Finally, we propose future perspectives regarding this new therapeutic strategy, highlighting the main challenges for future use in clinical practice.

Nose-to-brain co-delivery of drugs for glioblastoma treatment using nanostructured system.

Mutations on the epidermal growth factor receptor (EGFR), induction of angiogenesis, and reprogramming cellular energetics are all biological features acquired by tumor cells during tumor development, and also known as the hallmarks of cancer. Targeted therapies that combine drugs that are capable of acting against such concepts are of great interest, since they can potentially improve the therapeutic efficacy of treatments of complex pathologies, such as glioblastoma (GBM). However, the anatomical location and biological behavior of this neoplasm imposes great challenges for targeted therapies. A novel strategy that combines alpha-cyano-4-hydroxycinnamic acid (CHC) with the monoclonal antibody cetuximab (CTX), both carried onto a nanotechnology-based delivery system, is herein proposed for GBM treatment via nose-to-brain delivery. The biological performance of Poly (D,L-lactic-co-glycolic acid)/chitosan nanoparticles (NP), loaded with CHC, and conjugated with CTX by covalent bonds (conjugated NP) were extensively investigated. The NP platforms were able to control CHC release, indicating that drug release was driven by the Weibull model. An ex vivo study with nasal porcine mucosa demonstrated the capability of these systems to promote CHC and CTX permeation. Blot analysis confirmed that CTX, covalently associated to NP, impairs EGRF activation. The chicken chorioallantoic membrane assay demonstrated a trend of tumor reduction when conjugated NP were employed. Finally, images acquired by fluorescence tomography evidenced that the developed nanoplatform was effective in enabling nose-to-brain transport upon nasal administration. In conclusion, the developed delivery system exhibited suitability as an effective novel co-delivery approaches for GBM treatment upon intranasal administration.

Design of chitosan-based particle systems: A review of the physicochemical foundations for tailored properties.

Chitosan-based particles are widely proposed as biocompatible drug delivery systems with mucoadhesive and permeation enhancing properties. However, strategies on how to modulate the intended biological responses are still scarce. Considering that particle properties affect the biological outcome, the rational design of the synthesis variables should be proposed to engineer drug delivery systems with improved biological performance. The purpose of this review is to establish a deeper understanding of possible correlations between these variables and the particle properties from theoretical and experimental perspectives. The fundamental physicochemical knowledge of chitosan-based polyelectrolyte complexation and surface modification is discussed focusing on chitosan-TPP, polyelectrolyte complexes, and chitosan-surface modified PLGA or lipid particles. A set of design considerations is proposed to enable future investigation in the development of chitosan particles with modulated properties. The approach presented here contributes to the rational design of chitosan-based particles that meet different requirements for biological activities.

Validation of an innovative analytical method for simultaneous quantification of alpha-cyano-4-hydroxycinnamic acid and the monoclonal antibody cetuximab using HPLC from PLGA-based nanoparticles.

Accumulating evidence has been suggesting that combining two or more anticancer drugs can provide additive or synergistic effects, improving therapeutic efficacy and delaying resistance. Nowadays, advances in nanotechnology-based delivery systems have enabled the association of different drugs into a single carrier and provided therapeutic gains to the proposed regimen. However, a new strategy also requires innovative analytical approaches that assess loading capacity, biological performance, and also comprehend the mechanisms of action. Alpha-cyano-4-hydroxycinnamic acid (CHC) and the monoclonal antibody (mAb) cetuximab (CTX) are explored worldwide for their therapeutic benefits against multiple cancer cells. The present work aims to develop and validate a new method for simultaneous quantification of CHC and CTX in nanoparticulate systems by using reverse phase high-performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detection for CHC, and fluorescence detection for CTX. This method was designed following the guidelines of the International Conference on Harmonization ICH Q2 (R1) and the Food and Drug Administration (FDA) - Guidance for Bioanalytical Method Validation. Chromatographic separation was performed on a C18 column with the mobile phase composed by water, 0.1 % (v/v) trifluoroacetic acid (TFA) and acetonitrile (ACN)-0.1 % TFA on gradient mode at a flow rate of 0.6 mL/min. The performance of the present method was evaluated by system suitability; therefore, linearity, accuracy, precision, detection, limit of detection / limit of quantification, and robustness were also highlighted. Specificity was demonstrated by the chromatographic analyses of CHC and CTX, subjected to several informative stress conditions. The developed method was also successfully used for the first time to quantify the CHC and CTX content in poly(lactic-co-glycolic acid)-based nanoparticles. In conclusion, this new and rapid method presented acceptable analytical performance and can be helpful to simultaneously quantify CHC and CTX in future studies applied to anticancer therapy.

Modulating chitosan-PLGA nanoparticle properties to design a co-delivery platform for glioblastoma therapy intended for nose-to-brain route.

Nose-to-brain delivery is a promising approach to target drugs into the brain, avoiding the blood-brain barrier and other drawbacks related to systemic absorption, and enabling an effective and safer treatment of diseases such as glioblastoma (GBM). Innovative materials and technologies that improve residence time in the nasal cavity and modulate biological interactions represent a great advance in this field. Mucoadhesive nanoparticles (NPs) based on poly(lactic-co-glycolic acid) (PLGA) and oligomeric chitosan (OCS) were designed as a rational strategy and potential platform to co-deliver alpha-cyano-4-hydroxycinnamic acid (CHC) and the monoclonal antibody cetuximab (CTX) into the brain, by nasal administration. The influence of formulation and process variables (O/Aq volume ratio, Pluronic concentration, PLGA concentration, and sonication time) on the properties of CHC-loaded NPs (size, zeta potential, PDI and entrapment efficiency) was investigated by a two-level full factorial design (24). Round, stable nano-sized particles (213-875 nm) with high positive surface charge (+ 33.2 to + 58.9 mV) and entrapment efficiency (75.69 to 93.23%) were produced by the emulsification/evaporation technique. Optimal process conditions were rationally selected based on a set of critical NP attributes (258 nm, + 37 mV, and 88% EE) for further conjugation with CTX. The high cytotoxicity of CHC-loaded NPs and conjugated NPs was evidenced for different glioma cell lines (U251 and SW1088). A chicken chorioallantoic membrane assay highlighted the expressive antiangiogenic activity of CHC-loaded NPs, which was enhanced for conjugated NPs. The findings of this work demonstrated the potential of this nanostructured polymeric platform to become a novel therapeutic alternative for GBM treatment. Graphical abstract.

A novel strategy for glioblastoma treatment combining alpha-cyano-4-hydroxycinnamic acid with cetuximab using nanotechnology-based delivery systems.

Combination therapy that uses multiple drugs against different molecular targets should be considered as interesting alternatives for treating complex diseases such as glioblastoma (GBM). Drugs like alpha-cyano-4-hydroxycinnamic acid (CHC) and the monoclonal antibody cetuximab (CTX) are already explored for their capacity to act against different hallmarks of cancer. Previous reports suggest that the simultaneous use of these drugs, as a novel combining approach, might result in additive or synergistic effects. Therefore, advances in nanotechnology-based delivery systems will inevitably bring nano-mediated therapeutic gains to the proposed combination since they enable the association of different drugs into a single carrier. The current study provides indications that the new dual therapeutic strategy proposed, in association with nanotechnology, provides significative improvements when compared to the use of isolated drugs. Nanotechnological tools were employed by developing polymeric nanoparticles based on poly(lactic-co-glycolic acid) and chitosan for CHC encapsulation. Furthermore, these structures were conjugated with CTX by supramolecular forces. In summary, the encapsulation of the CHC drug into the nanoparticles increased its individual therapeutic capacity. In addition, conjugation with CTX seemed to enhance therapeutic efficacy, especially for U251 GBM cells. In conclusion, developed nanostructured delivery systems exhibited a set of favorable attributes and potential to be applied as a promising new alternative for GBM treatment. Graphical abstract .

Meglumine-based supra-amphiphile self-assembled in water as a skin drug delivery system: Influence of unfrozen bound water in the system bioadhesiveness.

Hexagonal liquid crystals and supramolecular polymers from meglumine-based supra-amphiphiles were developed as drug delivery systems to be applied on the skin. The influence of fatty acid unsaturation on the structure and mechanical properties was evaluated. Moreover, we have investigated the system biocompatibility and how the type of water could influence its bioadhesive properties. Meglumine-oleic acid (MEG-OA) was arranged as hexagonal liquid crystals at 30-70 wt% water content, probably due to its curvature and increased water solubility. Meglumine-stearic acid (MEG-SA) at 10-80 wt% water content self-assembled as a lamellar polymeric network, which can be explained by the low mobility of MEG-SA in water due to hydrophobic interactions between fatty acid chains and H-bonds between meglumine and water molecules. Both systems have shown suitable mechanical parameters and biocompatibility, making them potential candidates to encapsulate therapeutic molecules for skin delivery. Moreover, a strong positive correlation between the amount of unfrozen bound water in meglumine-based systems and the bioadhesion properties was observed. This work shows that a better understanding of the physicochemical properties of a drug delivery system is extremely important for the correlation with the desired biological response and, thus, improve the product performance for biomedical applications.

Alginate hydrogel improves anti-angiogenic bevacizumab activity in cancer therapy.

Anti-vascular endothelial growth factor (anti-VEGF) therapy applied to solid tumors is a promising strategy, yet, the challenge to deliver these agents at high drug concentrations together with the maintenance of therapeutic doses locally, at the tumor site, minimizes its benefits. To overcome these obstacles, we propose the development of a bevacizumab-loaded alginate hydrogel by electrostatic interactions to design a delivery system for controlled and anti-angiogenic therapy under tumor microenvironmental conditions. The tridimensional hydrogel structure produced provides drug stability and a system able to be introduced as a flowable solution, stablishing a depot after local administration. Biological performance by the chick embryo chorioallantoic membrane (CAM) assay indicated a pH-independent improved anti-angiogenic activity (∼50%) compared to commercial available anti-VEGF drug. Moreover, there was a considerable regression in tumor size when treated with this system. Immunohistochemistry highlighted a reduced number and disorganization of microscopic blood vessels resulting from applied therapy. These results suggest that the developed hydrogel is a promising approach to create an innovative delivery system that offers the possibility to treat different solid tumors by intratumoral administration.

Bilateral proliferative retinopathy as the initial presentation of chronic myeloid leukemia.

The authors report a rare case of a 48-year-old male with chronic myeloid leukemia (CML) who initially presented with a bilateral proliferative retinopathy. The patient complained of recent visual loss and floaters in both eyes (BE). Ophthalmologic evaluation revealed a best corrected visual acuity (BCVA) of 20/50 in the right eye and 20/200 in the left eye (LE). Fundoscopy showed the presence of bilateral peripheral capillary dropout with multiple retinal sea fan neovascularisations, which were confirmed on fluorescein angiography. Full blood count revealed hyperleukocytosis, thrombocytosis, anemia, and hyperuricemia. Bone marrow aspiration and biopsy showed the reciprocal chromosomal translocation t (9;22), diagnostic of CML. The patient was started on hydroxyurea, allopurinol and imatinib mesylate. He received bilateral panretinal laser photocoagulation and a vitrectomy was performed in the LE. The patient has been in complete hematologic, cytogenetic, and major molecular remission while on imatinib and his BCVA is 20/25 in BE.