Facile preparation of a pH-sensitive nano-magnetic targeted system to deliver doxorubicin to tumor tissues

A Novel Superparamagnetic Multifunctional Nerve Scaffold: A Remote Actuation Strategy to Boost In Situ Extracellular Vesicles Production for Enhanced Peripheral Nerve Repair

Extracellular vesicles (EVs) have inherent advantages over cell-based therapies in regenerative medicine because of their cargos of abundant bioactive cues. Several strategies are proposed to tune EVs production in vitro. However, it remains a challenge for manipulation of EVs production in vivo, which poses significant difficulties for EVs-based therapies that aim to promote tissue regeneration, particularly for long-term treatment of diseases like peripheral neuropathy. Herein, a superparamagnetic nanocomposite scaffold capable of controlling EVs production on-demand is constructed by incorporating polyethyleneglycol/polyethyleneimine modified superparamagnetic nanoparticles into a polyacrylamide/hyaluronic acid double-network hydrogel (Mag-gel). The Mag-gel is highly sensitive to a rotating magnetic field (RMF), and can act as mechano-stimulative platform to exert micro/nanoscale forces on encapsulated Schwann cells (SCs), an essential glial cell in supporting nerve regeneration. By switching the ON/OFF state of the RMF, the Mag-gel can scale up local production of SCs-derived EVs (SCs-EVs) both in vitro and in vivo. Further transcriptome sequencing indicates an enrichment of transcripts favorable in axon growth, angiogenesis, and inflammatory regulation of SCs-EVs in the Mag-gel with RMF, which ultimately results in optimized nerve repair in vivo. Overall, this research provides a noninvasive and remotely time-scheduled method for fine-tuning EVs-based therapies to accelerate tissue regeneration, including that of peripheral nerves.

Water-based ferrofluid with tunable stability and its significance in nuclear wastewater treatment

The treatment of nuclear wastewater is one of the most urgent and arduous tasks currently, but traditional adsorption materials are significantly limited in practice due to their high demands on auxiliary operations (e.g., shaking or centrifugation) caused by poor stability or recyclability. To tackle this challenge, a water-based ferrofluid composed of magnetic nanoparticles grown in polyethylenimine branches is reported and applied to nuclear wastewater treatment. It is demonstrated that the ferrofluid can keep stable spontaneously in a wide pH range (3-11) out of their ultra-small size, strong electropositivity as well as high charge buffering capacity to achieve shaker-free adsorption, and can be magnetically separated after the neutralization of their positive charge to achieve convenient recycle. Meanwhile, it is found that the ferrofluid shows wide pH/adsorbate applicability and strong ion selectivity in radionuclides absorption. Furthermore, it is anticipated to achieve maximum adsorption capacities for U(VI), Sr(II) and Co(II) as high as 331.5, 427.8 and 759.6 mg/g, respectively. With these characteristics, this ferrofluid outperforms other reported adsorbents. In conclusion, this work provides a practical and effective radioactive wastewater treatment strategy, and enlightens the development of materials for other applications facing the dilemma of incompatible stability and recyclability.

Multifunctional nanocarriers based on graphitic-C3N4 quantum dots for tumor-targeted, traceable and pH-responsive drug delivery

A multifunctional nanocarrier is developed for simultaneous targeted delivery, efficient tracking and cancer treatment at the cellular level.

Nanoformulations of doxorubicin: how far have we come and where do we go from here?

Nanotechnology, focused on discovery and development of new pharmaceutical products is known as nanopharmacology, and one research area this branch is engaged in are nanopharmaceuticals. The importance of being nano has been particularly emphasized in scientific areas dealing with nanomedicine and nanopharmaceuticals. Nanopharmaceuticals, their routes of administration, obstacles and solutions concerning their improved application and enhanced efficacy have been briefly yet comprehensively described. Cancer is one of the leading causes of death worldwide and evergrowing number of scientific research on the topic only confirms that the needs have not been completed yet and that there is a wide platform for improvement. This is undoubtedly true for nanoformulations of an anticancer drug doxorubicin, where various nanocarrriers were given an important role to reduce the drug toxicity, while the efficacy of the drug was supposed to be retained or preferably enhanced. Therefore, we present an interdisciplinary comprehensive overview of interdisciplinary nature on nanopharmaceuticals based on doxorubicin and its nanoformulations with valuable information concerning trends, obstacles and prospective of nanopharmaceuticals development, mode of activity of sole drug doxorubicin and its nanoformulations based on different nanocarriers, their brief descriptions of biological activity through assessing in vitro and in vivo behavior.

Poly (vinyl alcohol) microneedles: Fabrication, characterization, and application for transdermal drug delivery of doxorubicin

Poly (vinyl alcohol) microneedles were fabricated, characterized, and applied to enhance in vitro transdermal delivery of doxorubicin. The microneedles were fabricated using the micromolding technique with the drug load in different locations within the needle array. The polymer solution was assessed for rheological properties, drug dissolution, and chemical structurestudies. Microneedles (unloaded) and drug-loaded microneedles were characterized by optical microscopy, fluorescent microscopy, scanning electron microscopy, and drug release kinetics. Successful microporation of dermatomed human cadaver skin was demonstrated by dye binding, pore uniformity, histology, confocal laser microscopy, and skin integrity studies. The microneedles-mediated transdermal delivery of doxorubicin was investigated using vertical Franz diffusion cells. The fabricated microneedles were sharp, strong, and uniform. In vitro permeation studies showed that the microneedle-treated skin (4351.55 ± 560.87 ng/sq.cm) provided a significantly greater drug permeability than the untreated group (0.00 ± 0.00 ng/sq.cm, n = 4, p < 0.01). The drug location within the needle array was found to affect the drug release profile as well as its permeation into and across human skin. Skin microporation achieved by poly (vinyl alcohol) microneedles was found to enhance transdermal delivery of doxorubicin in vitro.

Fabrication, characterization and application of sugar microneedles for transdermal drug delivery

Aim: This study aimed to fabricate, characterize and use maltose microneedles for transdermal delivery of doxorubicin. Materials & methods: Microneedles were fabricated by micromolding technique and evaluated for dimensions, mechanical properties and in situ dissolution. Microporation of human cadaver skin was confirmed by dye binding, histology, pore uniformity, confocal laser microscopy and skin integrity measurement. In vitro permeation studies were performed on vertical Franz diffusion cells. Results: Maltose microneedles were sharp, mechanically uniform and rapidly dissolvable. Microneedle insertion resulted in a marked decrease in lag time and a significant increase in the permeation across and into human skin (p < 0.05). The skin delivery profile was used to predict the steady-state plasma concentration. Conclusion: Maltose microneedles are a promising physical technique to increase skin delivery.

Synthesis and characterization of mesoporous magnetic nanocomposites wrapped with chitosan gatekeepers for pH-sensitive controlled release of doxorubicin

Multifunctional nanocarriers based on the Fe₃O₄ nanoparticles core and mesoporous silica shell (mSiO₂) were synthesized for controlled drug release through magnetic targeting and pH-sensitive performances. The developed Fe₃O₄@mSiO₂ nanocarriers exhibited a suitable size (63nm) and good magnetic responsibility, doxorubicin (DOX) could be successfully loaded into the mesoporous of Fe₃O₄@mSiO₂ via electrostatic interaction, and the drug loading content and loading efficiency are 29.3% and 93.6%, respectively. The chitosan (CS) was employed to wrap the Fe₃O₄@mSiO₂-DOX as the blocking agent to inhibit premature drug release, and the final CS/Fe₃O₄@mSiO₂-DOX exhibited excellent pH-sensitivity, 86.1% DOX was released within 48h at pH4.0. Furthermore, all the release behaviors fit the Higuchi model very well and a purely diffusion-controlled process played a major role on DOX release from CS/Fe₃O₄@mSiO₂-DOX. In addition, MTT assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the CS/Fe₃O₄@mSiO₂-DOX had high anti-tumor activity, while the Fe₃O₄@mSiO₂ nanocarriers were practically non-toxic. Thus, our results revealed that the CS/Fe₃O₄@mSiO₂-DOX could play an important role in the development of intracellular delivery nanodevices for cancer therapy.

Facile synthesis of magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan hydrogel as MTX carriers for controlled drug release

In the present study, methotrexate (MTX)-encapsulated magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan were successfully prepared through a one-step gelation process, which is a very facile, economic and environmentally friendly route. The developed hydrogel beads exhibited homogeneous porous structure and super-paramagnetic responsibility. MTX can be successfully encapsulated into magnetic chitosan hydrogel beads, and the drug encapsulation efficiency (%) and encapsulation content (%) were 93.8 and 6.28%, respectively. In addition, the drug release studies in vitro indicated that the MTX-encapsulated magnetic chitosan hydrogel beads had excellent pH-sensitivity, 90.6% MTX was released from the magnetic chitosan hydrogel beads within 48 h at pH 4.0. WST-1 assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the MTX-encapsulated magnetic chitosan hydrogel beads had good cytocompatibility and high anti-tumor activity. Therefore, our results revealed that the MTX-encapsulated magnetic chitosan hydrogel beads would be a competitive candidate for controlled drug release in the area of targeted cancer therapy in the near future.

In vitro and in vivo chemo-phototherapy of magnetic TiO2 drug delivery system formed by pH-sensitive coordination bond

To achieve tumor-specific delivery of doxorubicin, TiO2@Fe3O4/PEI/delivery of doxorubicin conjugates were designed and synthesized. Fe3O4 could act as magnetically responsive carriers and enhance the visible light photodynamic activities of TiO2. Delivery of doxorubicin was conjugated via coordination bond. The drug release rate at pH 5.2 was much faster than that at pH 7.4, due to pH-sensitive coordination bond. Besides, TiO2@Fe3O4/PEI/delivery of doxorubicin showed high antitumor efficacy combining with phototherapy, good bio-safety, higher cellular uptake with an external magnetic field, and less toxicity in vitro and in vivo. These results suggested that TiO2@Fe3O4/PEI/delivery of doxorubicin may be promising for high tumor treatment efficacy with minimal side effects in future.