PVA/κ-carrageenan/Au/camptothecin/pegylated-polyurethane/paclitaxel nanofibers against lung cancer treatment

Gold nanoparticles, paclitaxel (PTX), and camptothecin (CMPT) were loaded into the PVA/κ-carrageenan/pegylated-PU composite and core–shell nanofibers prepared by two-nozzle and coaxial electrospinning methods. The capability of composite and core–shell nanofibers was investigated for the targeted delivery of anticancer drugs in lung cancer treatment. In vitro and in vivo release of PTX and CMPT were investigated to find the release mechanism from nanofibers compared to direct administration of pristine PTX and CMPT. The mean fiber diameter for composite and core–shell nanofibers with shell feeding rates of 0.3, 0.5, and 0.7 mL h⁻¹ was about 225, 330, 520, and 640 nm, respectively. In vivo release studies indicated that the blood concentration of CMPT and PTX for rats fed with core–shell nanofibers reached the highest values of 26.8 ± 0.04 μg mL⁻¹, and 26.5 ± 0.05 μg mL⁻¹ in 36 h, and 24 h and reduced slowly within 84 h, and 48 h, respectively. The maximum cytotoxicity was 75% in the presence PVA/κ-carrageenan/CMPT/Au/pegylated-PU/PTX core–shell nanofibers. In vivo antitumor activity results confirmed the synergic effect of Au, CMPT and PTX anticancer drugs on the reduction of tumor volume without change in mouse weight by the PVA/κ-carrageenan/CMPT/Au/pegylated PU/PTX core–shell nanofibers. The obtained results indicated that the simultaneous loading of CMPT and PTX anticancer drugs and Au nanoparticles is more beneficial for lung cancer treatment.

Core–shell nanofibers and in vivo release from core–shell nanofibers against lung cancer.

Biomedical Applications of Polyurethane Hydrogels, Polyurethane Aerogels and Polyurethane-Graphene Nanocomposite Materials

BACKGROUND

Increasing new emerging ill-healths have posed therapeutic challenges in modern medicine. Hence polyurethane hydrogels that comprise polyol, copolymer and extender could be prepared from diverse chemical compounds with adjuvants such as ascorbic acid, sorbitol among others. Their mechano-physicochemical properties are functions of their biological activities. Therefore there is need to assess their therapeutic potentials.

METHODS

literature were searched on synthesis and medical uses of polyurethane - hydrogels, polyurethane - aerogels and polyurethane - graphene nanocomposite materials, with a view to identifying their sources, synthesis, mechanical and physiochemical properties, biomedical applications, chirality, and the relevance of Lipinski's rule of five in the synthesis of oral polyurethane nanocomposite materials.

RESULTS

The prepared hydrogels and aerogels could be used as polymer carriers for intradermal, cutaneous and intranasal drugs. They can be fabricated and used as prosthetics. In addition the strength modulus (tensile stress-tensile strain ratio), biodegradability, biocompatibility and non-toxic effects of the polyurethane hydrogels and aerogels are the highly desirable properties. However, body and environmental temperatures may contribute to their instability, hence there is need to improve on the synthesis of aerogels and hydrogels of polyurethane that can last for many years. Alcoholism, diabetes, pyrogenic diseases, mechanical and physical forces, and physiological variability may also reduce the life span of polyurethane aerogels and hydrogels.

CONCLUSION

Synthesis of polyurethane hydrogel-aerogel complex that can be used in complex, rare biomedical cases is of paramount importance. These hydrogels and aerogels may be hydrophobic, hydrophilic, aerophobic-aerophilic or amphiphilic and sometimes lipophilic depending on structural components and the intended biomedical uses. Polyurethane graphene nanocomposite materials are used in the treatment of a myriad of diseases including cancer and bacterial infection.

CD44-targeted pH-responsive micelles for enhanced cellular internalization and intracellular on-demand release of doxorubicin

Poor cellular uptake and slow intracellular drug release remain the main barriers for the efficient application of micellar delivery system. Taking advantage of the overexpressed CD44 receptor and mild acidic microenvironment of tumour cells, CD44-targeted pH-responsive micelles based on the self-assembly of histidine-hyaluronic acid-dodecylamine (His-HA-DA) were prepared for the delivery of doxorubicin (DOX). These micelles exhibited pH-responsive behaviour with increased particle size, decreased encapsulation efficiency (EE%) of DOX and rapid release of DOX triggered by low pH. Compared with free DOX, DOX/HHD exhibited relatively high cellular uptake mainly via the CD44-mediated endocytosis. The on-demand intracellular release of DOX from DOX/HHD led to improved cytotoxicity. DOX/HHD also showed great penetration efficiency in 3D tumour spheres in vitro. Moreover, these micelles with suitable particle size gained excellent tumour-targeting effects, as well as improved anti-tumour effects and reduced side effects in vivo. In conclusion, these micelles with CD44 targeted and pH-responsive behaviours provide a promising strategy for the efficient delivery of anti-tumour drugs in vivo.

Dual-sensitive chitosan derivative micelles for site-specific drug release in the treatment of chicken coccidiosis

Here, we report a “dual-sensitive” drug delivery platform packaged with anti-coccidia drug diclazuril (DIC) applied in the field of intestinal-targeted administration.

Reduction responsive and surface charge switchable polyurethane micelles with acid cleavable crosslinks for intracellular drug delivery

Previously we synthesized redox sensitive polyurethane micelles, core crosslinked by diisocyanates (PU-CCL).

Synthesis of polyurethanes with pendant azide groups attached on the soft segments and the surface modification with mPEG by click chemistry for antifouling applications

Polyurethane with pendant azide groups on the soft segment (PU-GAP) was prepared in this study to further increase the content of reactive azide groups and improve their surfaces enrichment for further functionalization. Polymer diols with pendant azide groups (GAP) were prepared by transforming the pendant chlorine groups at polyepichlorohydrin (PECH) into azide groups with sodium azide. The prepared PECH, GAP and PU-GAP was characterized by GPC, ¹H NMR and FTIR. Propargylic mPEG (mPEG-alkyne) was used as model surface modification reagents which was grafted on the prepared azido containing polyurethane films via click chemistry. The surface morphology, chemical composition and wettabilities were studied by SEM, XPS and water contact angle (WCA) analysis, respectively. SEM results demonstrated different surface topologies between mPEG modified PU surface and original PU surface. XPS and WCA analysis proved the successful grafting of mPEG on the pendant azide groups of PUs. The mPEG modified PU surfaces demonstrated good antifouling activities against model bacteria and mPEG with larger molecular weights modified surfaces showed better resistance efficiency to attachment of bacteria. Therefore, the surface reactive polyurethane we prepared can be a universal platform for further functionalization according actual applications.

Polyurethane with pendant azide groups on the soft segment which can be an universal platform for further functionalization according actual applications.

Acetal-Linked Paclitaxel Polymeric Prodrug Based on Functionalized mPEG-PCL Diblock Polymer for pH-Triggered Drug Delivery

The differences in micro-environment between cancer cells and the normal ones offer the possibility to develop stimuli-responsive drug-delivery systems for overcoming the drawbacks in the clinical use of anticancer drugs, such as paclitaxel, doxorubicin, and etc. Hence, we developed a novel endosomal pH-sensitive paclitaxel (PTX) prodrug micelles based on functionalized poly(ethylene glycol)-poly(ε-caprolactone) (mPEG-PCL) diblock polymer with an acid-cleavable acetal (Ace) linkage (mPEG-PCL-Ace-PTX). The mPEG-PCL-Ace-PTX₅ with a high drug content of 23.5 wt % was self-assembled in phosphate buffer (pH 7.4, 10 mM) into nanosized micelles with an average diameter of 68.5 nm. The in vitro release studies demonstrated that mPEG-PCL-Ace-PTX₅ micelles was highly pH-sensitive, in which 16.8%, 32.8%, and 48.2% of parent free PTX was released from mPEG-PCL-Ace-PTX₅ micelles in 48 h at pH 7.4, 6.0, and 5.0, respectively. Thiazolyl Blue Tetrazolium Bromide (MTT) assays suggested that the pH-sensitive PTX prodrug micelles displayed higher therapeutic efficacy against MCF-7 cells compared with free PTX. Therefore, the PTX prodrug micelles with acetal bond may offer a promising strategy for cancer therapy.