Advances on Porous Nanomaterials for Biomedical Application (Drug Delivery, Sensing, and Tissue Engineering)

Exploring the synergy between bioluminescence and nanomaterials: Innovations in analytical and therapeutic applications

The application of bioluminescent luciferin-luciferase systems for visualizing and stimulating various processes in living systems is of great interest due to its specific nature and high signal-to-noise ratio. Nanomaterials can finely manipulate multiple parameters of the bioluminescent systems, including the enzyme stability, intensity, and duration of the irradiation. Also, bioluminescence can affect the properties of a nanomaterial, namely, to carry out BRET, to trigger cascades of various photochemical transformations. Here we summarize cases of the interplay between nanomaterials and various bioluminescent systems to improve various biosensors, biovisualization in cellulo, in vivo, and for therapy over the past twenty years. We reviewed interactions between a wide range of nanomaterials and bioluminescent systems, including bacterial and genetically encoded luciferases. This review aims to serve as a comprehensive guide for developing bioluminescent multimodal nanoplatforms for analytic applications and therapy.

Foaming of Bio-Based PLA/PBS/PBAT Ternary Blends with Added Nanohydroxyapatite Using Supercritical CO2: Effect of Operating Strategies on Cell Structure

This study explored the innovative foaming behavior of a novel biodegradable polymer blend consisting of polylactic acid/poly(butylene succinate)/poly(butylene adipate-co-terephthalate) (PLA/PBS/PBAT) enhanced with nanohydroxyapatite (nHA), using supercritical carbon dioxide (SCCO2) as an environmentally friendly physical foaming agent. The aim was to investigate the effects of various foaming strategies on the resulting cell structure, aiming for potential applications in tissue engineering. Eight foaming strategies were examined, starting with a basic saturation process at high temperature and pressure, followed by rapid decompression to ambient conditions, referred to as the (1T-1P) strategy. Intermediate temperature and pressure variations were introduced before the final decompression to evaluate the impact of operating parameters further. These strategies included intermediate-temperature cooling (2T-1P), intermediate-temperature cooling with rapid intermediate decompression (2T-2P), and intermediate-temperature cooling with gradual intermediate decompression (2T-2P, stepwise ΔP). SEM imaging revealed that the (2T-2P, stepwise ΔP) strategy produced a bimodal cell structure featuring small cells ranging from 105 to 164 μm and large cells between 476 and 889 μm. This study demonstrated that cell size was influenced by the regulation of intermediate pressure reduction and the change in intermediate temperature. The results were interpreted based on classical nucleation theory, the gas solubility principle, and the effect of polymer melt strength. Foaming results of average cell size, cell density, expansion ratio, porosity, and opening cell content are reported. The hydrophilicity of various foamed polymer blends was evaluated by measuring the water contact angle. Typical compressive stress-strain curves obtained using DMA showed a consistent trend reflecting the effect of foam stiffness.

Anionic polyelectrolyte-regulated cellulose nanocrystal-based hydrogels for controllable drug release

The application of inorganic salt-regulated Hofmeister effects in cellulose nanocrystals (CNC)-based hydrogels is hindered by limitations, including poor biocompatibility and difficulties in achieving precise drug release. In this study, we show that the anionic polyelectrolyte regulated Hofmeister effect promotes the aggregation and crystallization of CNC and polyvinyl alcohol (PVA) chains. This structural transformation significantly enhances the controllability of drug release in CNC-based hydrogels. The incorporation of anionic polyelectrolytes into CNC-based hydrogels creates a semi-interpenetrating polymer network (semi-IPN), significantly enhancing their mechanical properties and improving in vitro drug release controllability. Our hydrogel exhibits significant flexibility in controlling both drug release duration and capacity, with adjustable release times ranging from 16 to 52 h and tunable drug release capacities between 10.13 mg/g and 19.21 mg/g. Furthermore, antibacterial and cytotoxicity assays confirm its favorable biocompatibility and moderate antibacterial properties. Overall, our research findings emphasize that the preparation of cellulose-based hydrogels using polyelectrolytes has certain flexible regulatory functions in drug release.

Recent developments in pillar[5]arene-based nanomaterials for cancer therapy

Nanomaterials possess unique size characteristics, enabling them to cross tissue gaps, penetrate the blood-brain barrier and endothelial cells, and release drugs at the cellular level. Additionally, the surface of nanomaterials is readily functionalized, endowing them with good biocompatibility, low biotoxicity, and specific targeting. All these advantages render nanomaterials broad application prospects in tumor therapy. Pillar[5]arenes are a new category of macrocyclic host compounds featuring rich host-guest properties and diverse environmental responses. In recent years, by combining the advantages of pillar[5]arenes and nanomaterials, the application of pillar[5]arene-based nanomaterials in tumor therapy has drawn extensive attention from scientists. In this review, we summarize five distinct types of pillar[5]arene-based nanomaterials: (1) pillar[5]arene-modified inorganic nanomaterials; (2) pillar[5]arene-modified organic porous materials; (3) pillar[5]arene-modified organic/inorganic hybrid materials; (4) nanomaterials self-assembled from pillar[5]arene-based host-guest complexes; (5) nanomaterials self-assembled from amphiphilic pillar[5]arenes. Moreover, the different tumor treatment modes of these nanomaterials, including chemotherapy, photodynamic therapy, photothermal therapy, gene therapy, and multimodal synergistic therapy, are also elaborated in detail.

Current status and future developments of biopolymer microspheres in the field of pharmaceutical preparation

Polymer composite microspheres offer several advantages including highly designable structural properties, adjustable micro-nano particle size distribution, easy surface modification, large specific surface area, and high stability. These features make them valuable in various fields such as medicine, sensing, optics, and display technologies, with significant applications in clinical diagnostics, pathological imaging, and drug delivery in the medical field. Currently, microspheres are primarily used in biomedical research as long-acting controlled-release agents and targeted delivery systems, and are widely applied in bone tissue repair, cancer treatment, and wound healing. Different types of polymer microspheres offer distinct advantages and application prospects. Efforts are ongoing to transition successful experimental research to industrial production by expanding various fabrication technologies. This article provides an overview of materials used in microsphere manufacturing, different fabrication methods, modification techniques to enhance their properties and applications, and discusses the role of microspheres in drug delivery engineering.

Investigation on the Drug Release Efficacy of the Ibuprofen-Loaded ZIF-8/Fe3O4 NPs Nanocarrier

In this work, a one-pot multicomponent synthesis of the ibuprofen-loaded Fe3O4 nanoparticles-supported zeolitic imidazolate framework-8 (Ibu-ZIF-8/Fe3O4 NPs) nanohybrid was carried out. The ZIF-8/Fe3O4 NPs nanohybrid was used as a drug carrier for the in vitro release of ibuprofen in a PBS solution. The structure and morphology of the synthesized materials were investigated by powder X-ray diffraction (PXRD) analysis, transmission electron microscopy (TEM) analysis, UV-visible absorption studies, FTIR spectroscopy, and thermogravimetric analysis (TGA). The ibuprofen release kinetics was studied by UV-visible spectroscopy. The mechanism of drug delivery was thoroughly investigated and the Higuchi model was found as the best-fitted model for the ibuprofen release study. The 20 wt % Fe3O4 NPs-supported ZIF-8 nanohybrid exhibited more than 95% ibuprofen release efficiency in phosphate buffer saline of pH 7.4 within 2 h. The separation ability of the nanohybrid was very good, and it was easily separated by a simple commercial magnet. In order to investigate the cell viability, the cytotoxicity of ZIF-8, Fe3O4 NPs, and ZIF-8/20 wt % Fe3O4 NPs was investigated using MTT assays against Leishmania donovani promastigotes. The ZIF-8/20 wt % Fe3O4 NPs nanohybrid carrier exhibited a cell growth inhibition effect with a high correlation coefficient and low probability (p) values. The high release of drug molecules may be due to the more open site of the ZIF-8/Fe3O4 NPs nanohybrid. The drug release profile suggests that the nanohybrid can be potentially used as a drug carrier for targeted drug delivery systems.

Biocompatibility of intraperitoneally implanted TEMPO-oxidized cellulose nanofiber hydrogels for antigen delivery in Atlantic salmon (Salmo salar L.) vaccines

Disease outbreaks are a major impediment to aquaculture production, and vaccines are integral for disease management. Vaccines can be expensive, vary in effectiveness, and come with adjuvant-induced adverse effects, causing fish welfare issues and negative economic impacts. Three-dimensional biopolymer hydrogels are an appealing new technology for vaccine delivery in aquaculture, with the potential for controlled release of multiple immunomodulators and antigens simultaneously, action as local depots, and tunable surface properties. This research examined the intraperitoneal implantation of a cross-linked TEMPO cellulose nanofiber (TOCNF) hydrogel formulated with a Vibrio anguillarum bacterin in Atlantic salmon with macroscopic and microscopic monitoring to 600-degree days post-implantation. Results demonstrated a modified passive integrated transponder tagging (PITT) device allowed for implantation of the hydrogel. However, the Atlantic salmon implanted with TOCNF hydrogels exhibited a significant foreign body response (FBR) compared to sham-injected negative controls. The FBR was characterized by gross and microscopic external and visceral proliferative lesions, granulomas, adhesions, and fibrosis surrounding the hydrogel using Speilberg scoring of the peritoneum and histopathology of the body wall and coelom. Acutely, gross monitoring displayed rapid coagulation of blood in response to the implantation wound with development of fibrinous adhesions surrounding the hydrogel by 72 h post-implantation consistent with early stage FBR. While these results were undesirable for aquaculture vaccines, this work informs on the innate immune response to an implanted biopolymer hydrogel in Atlantic salmon and directs future research using cellulose nanomaterial formulations in Atlantic salmon for a new generation of aquaculture vaccine technology.

Mesoporous Polydopamine-Encapsulated Fluorescent Nanodiamonds: A Versatile Platform for Biomedical Applications

Fluorescent nanodiamonds (FNDs) are versatile nanomaterials with promising properties. However, efficient functionalization of FNDs for biomedical applications remains challenging. In this study, we demonstrate mesoporous polydopamine (mPDA) encapsulation of FNDs. The mPDA shell is generated by sequential formation of micelles via self-assembly of Pluronic F127 (F127) with 1,3,5-trimethyl benzene (TMB) and composite micelles via oxidation and self-polymerization of dopamine hydrochloride (DA). The surface of the mPDA shell can be readily functionalized with thiol-terminated methoxy polyethylene glycol (mPEG-SH), hyperbranched polyglycerol (HPG), and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). The PEGylated FND@mPDA particles are efficiently taken up by, and employed as a fluorescent imaging probe for, HeLa cells. HPG-functionalized FND@mPDA is conjugated with an amino-terminated oligonucleotide to detect microRNA via hybridization. Finally, the increased surface area of the mPDA shell permits efficient loading of doxorubicin hydrochloride. Further modification with TPGS increases drug delivery efficiency, resulting in high toxicity to cancer cells.

Recent Progress of the Preparation and Application of Electrospun Porous Nanofibers

Electrospun porous nanofibers have gained a lot of interest recently in various fields because of their adjustable porous structure, high specific surface area, and large number of active sites, which can further enhance the performance of materials. This paper provides an overview of the common polymers, preparation, and applications of electrospun porous nanofibers. Firstly, the polymers commonly used to construct porous structures and the main pore-forming methods in porous nanofibers by electrospinning, namely the template method and phase separation method, are introduced. Secondly, recent applications of electrospun porous nanofibers in air purification, water treatment, energy storage, biomedicine, food packaging, sensor, sound and wave absorption, flame retardant, and heat insulation are reviewed. Finally, the challenges and possible research directions for the future study of electrospun porous nanofibers are discussed.