Supercritical CO2 assisted preparation of chitosan-based nano-in-microparticles with potential for efficient pulmonary drug delivery

Targeted delivery of the metastasis-specific tumour homing TMTP1 peptide to non-small-cell lung cancer (NSCLC) using inhalable hybrid nano-assemblies

Lung cancer is one of the most fatal malignancies, with the highest death rate (∼19%), and the NSCLC type accounts for ∼85% of lung cancers. In the search for new treatments, antimicrobial peptides have received much attention due to their propensity for selective destruction of cancer cells. In the current study, we evaluated the efficacy of the metastasis-specific tumour-homing-TMTP1 peptide against lung cancer using inhalable hybrid nano-assemblies of the PEG-PLGA copolymer as a carrier for pulmonary delivery which was assessed for aerodynamic and physicochemical properties, along with the peptide-release profile, physical stability, cellular uptake and biocompatibility, generation of reactive oxygen species, cell migration, autophagic flux, and apoptotic cell death in A549 lung cancer cells. Optimization of inhaled dose, lung retention, and efficacy studies was conducted to evaluate the formulation in an NNK (nicotine-derived nitrosamine ketone) induced tumour-bearing lung cancer murine model. After inhalation, the formulation with nano-scale physiognomies showed good lung deposition, retention, and metabolic stability. The inhalable nano-assemblies have shown enhanced generation of reactive oxygen species with increased autophagy flux and apoptotic cell death. Pre-clinical animal trials show substantial tumour regression by inhalable TMTP1-based nano-formulation with limited side effects. Our results on metastasis targeting and tumour-homing peptide TMTP1 demonstrate its effective tumour targeting and tumour-killing efficacy and provide a reference for the development of new therapeutics for NSCLC.

The Effect of Sub- and Near-Critical Carbon Dioxide Assisted Manufacturing on Medical Thermoplastic Polyurethane

Incorporating thermally labile active pharmaceutical ingredients for manufacturing multifunctional polymeric medical devices is restricted due to their tendency to degrade in the hot melt extrusion process. In this study, the potential of sub- and near-critical carbon dioxide (CO2) as a reversible plasticiser was explored by injecting it into a twin-screw hot melt extrusion process of Pellethane thermoplastic polyurethane to decrease its melt process temperature. Its morphological, throughput, thermal, rheological, and mechanical performances were also evaluated. The resultant extrudates were characterised using scanning electron microscopy, parallel plate rotational rheometer, differential scanning calorimetry, thermogravimetric analysis, and tensile testing. The process temperature decreased from 185 to 160 °C. The rheology indicated that the reduction in melt viscosity was from 690 Pa.s to 439 Pa.s (36%) and 414 Pa.s (40%) at 4.14 and 6.89 MPa, respectively. The tensile modulus in the elastomeric region is enhanced from 5.93 MPa, without CO2 to 7.71 MPa with CO2 at both 4.14 and 6.89 MPa. The results indicate that the employment of both sub- and near-critical CO2 as a processing aid is a viable addition to conventional hot melt extrusion and that they offer more opportunities for thermosensitive drugs to be more stable in the molten stream of Pellethane thermoplastic polyurethane.

Advances in Chitosan-Based Nanoparticles for Drug Delivery

Nanoparticles (NPs) have an outstanding position in pharmaceutical, biological, and medical disciplines. Polymeric NPs based on chitosan (CS) can act as excellent drug carriers because of some intrinsic beneficial properties including biocompatibility, biodegradability, non-toxicity, bioactivity, easy preparation, and targeting specificity. Drug transport and release from CS-based particulate systems depend on the extent of cross-linking, morphology, size, and density of the particulate system, as well as physicochemical properties of the drug. All these aspects have to be considered when developing new CS-based NPs as potential drug delivery systems. This comprehensive review is summarizing and discussing recent advances in CS-based NPs being developed and examined for drug delivery. From this point of view, an enhancement of CS properties by its modification is presented. An enhancement in drug delivery by CS NPs is discussed in detail focusing on (i) a brief summarization of basic characteristics of CS NPs, (ii) a categorization of preparation procedures used for CS NPs involving also recent improvements in production schemes of conventional as well as novel CS NPs, (iii) a categorization and evaluation of CS-based-nanocomposites involving their production schemes with organic polymers and inorganic material, and (iv) very recent implementations of CS NPs and nanocomposites in drug delivery.