Different drug loading methods and antibiotic structure modulate the efficacy of polydopamine nanoparticles as drug nanocarriers

Combating chemoresistance: Current approaches & nanocarrier mediated targeted delivery

Chemoresistance, a significant challenge in effective cancer treatment needs clear elucidation of the underlying molecular mechanism for the development of novel therapeutic strategies. Alterations in transporter pumps, oncogenes, tumour suppressor genes, mitochondrial function, DNA repair processes, autophagy, epithelial-mesenchymal transition (EMT), cancer stemness, epigenetic modifications, and exosome secretion lead to chemoresistance. Despite notable advancements in targeted cancer therapies employing both small molecules and macromolecules success rates remain suboptimal due to adverse effects like drug efflux, target mutation, increased mortality of normal cells, defective apoptosis, etc. This review proposes an advanced nanotechnological technique precisely targeting molecular determinants of chemoresistance which holds promise for enhancing cancer treatment efficacy. Further, the review explores various cancer hallmarks and pathways implicated in chemoresistance, current therapeutic modalities, and their limitations. It advocates the combination of nanoparticle-conjugated conventional drugs and natural compounds to specifically target molecular pathways that can potentially reverse or minimize chemoresistance incidences in cancer patients.

Antimicrobial and anti-inflammatory effects of polyethyleneimine-modified polydopamine nanoparticles on a burn-injured skin model

Chronic infections involving bacterial biofilms pose significant treatment challenges due to the resilience of biofilms against existing antimicrobials. Here, we introduce a nanomaterial-based platform for treating Staphylococcus epidermidis biofilms, both in isolation and within a biofilm-infected burn skin model. Our approach leverages biocompatible and photothermal polydopamine nanoparticles (PDNP), functionalized with branched polyethyleneimine (PEI) and loaded with the antibiotic rifampicin, to target bacteria dwelling within biofilms. A key innovation of our method is its ability to not only target planktonic S. epidermidis but also effectively tackle biofilm-embedded bacteria. We demonstrated that PDNP-PEI interacts effectively with the bacterial surface, facilitating laser-activated photothermal eradication of planktonic S. epidermidis. In a 3D skin burn injury model, PDNP-PEI demonstrates anti-inflammatory and reactive oxygen species (ROS)-scavenging effects, reducing inflammatory cytokine levels and promoting healing. The rifampicin-loaded PDNP-PEI (PDNP-PEI-Rif) platform further shows significant efficacy against bacteria inside biofilms. The PDNP-PEI-Rif retained its immunomodulatory activity and efficiently eradicated biofilms grown on our burn-injured 3D skin model, effectively addressing the challenges of biofilm-related infections. This achievement marks a significant advancement in infection management, with the potential for a transformative impact on clinical practice.

Inhalable Nano Formulation of Cabazitaxel: A Comparative Study with Intravenous Route

Chemotherapy is generally given by intravenous (IV) administration which provides higher bioavailability than other systemic routes. However, in the case of lung cancer, the pulmonary (INH) route is the other choice for inhalable formulations. In the study, biochemical and histological parameters of Cabazitaxel (CBZ) free (2 mg kg-1) and nanoparticle (NP) (2 mg kg-1 CBZ equivalent) formulations are investigated after IV and INH administration in rats. The nanoformulation of CBZ is obtained using PEGylated polystyrene (PEG-PST) nanoparticles obtained by PISA. While a nose and head-only device is used for INH administration, a jugular vein is used as the IV route. Blood samples (blank, 24 h, and 48 h) are collected via carotid artery cannulas without handling in metabolism cages. According to biochemical parameters, free CBZ formulation applied via IV or INH route shows higher systemic toxicity. On the other hand, the nanoformulation of CBZ showed no signs of toxicity in both IV or INH routes. Higher and longer retention is observed in the case of inhaled nanoformulation. Histological analysis showed higher alveolar macrophage migration for inhaled nanoformulation due to enhanced retention. Results showed that nanotechnology and the lung defense system gave the advantage to end up with an inhalable nanomedicine formulation for lung cancer.

The Use of Photoactive Polymeric Nanoparticles and Nanofibers to Generate a Photodynamic-Mediated Antimicrobial Effect, with a Special Emphasis on Chronic Wounds

This review is concerned with chronic wounds, with an emphasis on biofilm and its complicated management process. The basics of antimicrobial photodynamic therapy (PDT) and its underlying mechanisms for microbial eradication are presented. Intrinsically active nanocarriers (polydopamine NPs, chitosan NPs, and polymeric micelles) that can further potentiate the antimicrobial photodynamic effect are discussed. This review also delves into the role of photoactive electrospun nanofibers, either in their eluting or non-eluting mode of action, in microbial eradication and accelerating the healing of wounds. Synergic strategies to augment the PDT-mediated effect of photoactive nanofibers are reviewed.