Core–shell nanostructures are powerful platforms for the development of novel nanoscale drug delivery systems with sustained drug release profiles. Coaxial electrospinning is facile and convenient for creating medicated core–shell nanostructures with elaborate designs with which the sustained-release behaviors of drug molecules can be intentionally adjusted. With resveratrol (RES) as a model for a poorly water-soluble drug and cellulose acetate (CA) and PVP as polymeric carriers, a brand-new electrospun core–shell nanostructure was fabricated in this study. The guest RES and the host CA molecules were designed to have a reverse gradient distribution within the core–shell nanostructures. Scanning electron microscope and transmission electron microscope evaluations verified that these nanofibers had linear morphologies, without beads or spindles, and an obvious core–shell double-chamber structure. The X-ray diffraction patterns and Fourier transform infrared spectroscopic results indicated that the involved components were highly compatible and presented in an amorphous molecular distribution state. In vitro dissolution tests verified that the new core–shell structures were able to prevent the initial burst release, extend the continuous-release time period, and reduce the negative tailing-off release effect, thus ensuring a better sustained-release profile than the traditional blended drug-loaded nanofibers. The mechanism underlying the influence of the new core–shell structure with an RES/CA reverse gradient distribution on the behaviors of RES release is proposed. Based on this proof-of-concept demonstration, a series of advanced functional nanomaterials can be similarly developed based on the gradient distributions of functional molecules within electrospun multi-chamber nanostructures.

Electrospun nanofibers have shown their advantages for applications in a wide variety of scientific fields thanks to their unique properties. Meanwhile, electrospinning is closely following the fast development of nano science and nanotechnology to move forward to smaller (pico-technology), more complicated nanostructures/nanodevices and more order (all kinds of nano arrays). Particularly, multiple-fluid electrospinning has the strong capability of creating nanostructures from a structural spinneret in a single-step and a straightforward “top-down” manner, holding great promise for creation on a large scale. This review is just to conclude the state-of-art studies on the related topics and also point out that the future directions of environmental detection require chemosensors, while the improvement of sensors requires new chemically synthesized functional substances, new nanostructured materials, application convenience, and functional integration or synergy. Based on the developments of electrospinning, more and more possibilities can be drawn out for detecting environmental pollutants with electrospun nanostructures as the strong support platform.

In this nano era, nanomaterials and nanostructures are popular in developing novel functional materials. However, the combinations of materials at micro and macro scales can open new routes for developing novel trans-scale products with improved or even new functional performances. In this work, a brand-new hybrid, containing both nanofibers and microparticles, was fabricated using a sequential electrohydrodynamic atomization (EHDA) process. Firstly, the microparticles loaded with drug (berberine hydrochloride, BH) molecules in the cellulose acetate (CA) were fabricated using a solution electrospraying process. Later, these microparticles were suspended into a co-dissolved solution that contained BH and a hydrophilic polymer (polypyrrolidone, PVP) and were co-electrospun into the nanofiber/microparticle hybrids. The EHDA processes were recorded, and the resultant trans-scale products showed a typical hybrid topography, with microparticles distributed all over the nanofibers, which was demonstrated by SEM assessments. FTIR and XRD demonstrated that the components within the hybrids were presented in an amorphous state and had fine compatibility with each other. In vitro dissolution tests verified that the hybrids were able to provide the designed dual-step drug release profiles, a combination of the fast release step of BH from the hydrophilic PVP nanofibers through an erosion mechanism and the sustained release step of BH from the insoluble CA microparticles via a typical Fickian diffusion mechanism. The present protocols pave a new way for developing trans-scale functional materials.

In this study, an oral drug nanocrystals self-stabilized Pickering emulsion (NSSPE), which used nanocrystals of a poorly soluble ingredient from Puerariae Radix called puerarin as solid particle stabilizers and Ligusticum chuanxiong essential oil since the main oil phase had been developed to improve the oral bioavailability of puerarin. The appearance of emulsions, size and zeta potential of droplets, and content of puerarin in emulsified layer during a storage of six months at 4, 25, and 40 °C were investigated. The centrifugation stability at 4000× g was also studied. The micro-structure of emulsion droplets was characterized by a scanning electron micrograph (SEM), confocal laser scanning microscopy (CLSM), a fluorescence microscope (FM), and differential scanning calorimetry (DSC). The in vivo oral bioavailability of puerarin NSSPE was investigated in rats. Results showed that appearances of puerarin NSSPE kept stable after centrifugation at 4000× g for 15 min or storage for six months at 4, 25, and 40 °C. SEM, CLSM, FM, and DSC showed that the puerarin NSSPE had a stable core-shell structure of emulsion droplets formed by the adsorption of puerarin nanocrystals on the surface of oil droplets of mixed oil of Ligusticum chuanxiong essential oil and Labrafil M 1944 CS (9:1, v/v). The relative bioavailability of puerarin NSSPE to puerarin coarse powder suspension, nanocrystal suspension, and surfactant emulsion were 262.43%, 155.92%, and 223.65%, respectively. All these results indicated that puerarin nanocrystals could stabilize Pickering emulsion of Ligusticum chuanxiong essential oil without any other stabilizers and Pickering emulsion could improve the oral bioavailability of puerarin, which suggests that the drug nanocrystal self-stabilized Pickering emulsion as a promising oral drug delivery system for Traditional Chinese Medicine containing poorly soluble ingredients and volatile oils.

Batch production of nanomaterials is highly desired for developing commercial nanoproducts. Here, a brand-new electrospinning method, termed hole electrospinning, was developed for batch production of drug-loaded polymeric nanofibers. Using resveratrol and polyvinylpyrrolidone as model drug and filament-forming matrix, respectively, both hole and single-needle electrospinning were conducted. The resultant nanofibrous films were compared in terms of morphology, physical and thermal properties, mechanical performance, fast-dissolution rate, and antioxidant activity. Analytical and characterization results verified that nanofibers from different processes showed no significant differences in morphology, diameter, porosity, tensile strength, amorphous state, fast-dissolution performance and antioxidant activity. However, hole electrospinning provided 13.3-fold higher productivity than single-needle electrospinning, better drug encapsulation efficiency (97.3 ± 4.5% versus 83.7 ± 6.1%), and higher energy efficiency (0.0393 W/g versus 0.1247 W/g). Based on the protocols reported here, not only was a batch nano-conversion method for polymeric engineering developed, but also an attractive approach for the large-scale production of various complex configurations was proposed for potential commercial nanostructure-based products.

To overcome the limitations of traditional motion sickness medications—slow onset of action, short duration of efficacy, and poor patient compliance—this study employed coaxial electrospinning technology. Poly(lactic acid) (PLA) and polyvinylpyrrolidone K90 (PVP K90) were used as composite carrier materials. The sheath layer is composed of highly hydrophilic PVP K90, loaded with the antihistamine diphenhydramine (DPH). The core layer, composed of biodegradable PLA with excellent sustained-release properties, carries the anticholinergic drug scopolamine hydrobromide (SH). This core–sheath nanostructured nanofiber sublingual film delivers dual anti-motion sickness drugs. A series of characterization tests revealed that the sublingual membrane exhibits a linear morphology with a distinct core–shell nanostructure. The drugs DPH and SH are distributed in an amorphous state within the sheath and core layers, respectively. Wetting performance tests indicate that the membrane’s wettability falls between those of monofilament membranes. In vitro drug release experiments revealed that DPH exhibited a “rapid onset + sustained release” biphasic profile, with cumulative release reaching 60% within 2 h and approaching complete release by 10 h, primarily via Fickian diffusion (n = 0.30). SH exhibited prolonged sustained release, approaching complete release at 12 h via non-Fickian diffusion (n = 0.55). Cytotoxicity and vital/necrotic staining experiments mutually corroborated that cell viability remained above 80%, further validating the safety and efficacy of PLA/PVP as a combined drug delivery carrier. This study provides a novel delivery system for motion sickness treatment, offering significant theoretical value and broad clinical application prospects.