Nanotechnology-Based Drug Delivery Systems for Honokiol: Enhancing Therapeutic Potential and Overcoming Limitations

Honokiol (HNK) is a small-molecule polyphenol that has garnered considerable attention due to its diverse pharmacological properties, including antitumor, anti-inflammatory, anti-bacterial, and anti-obesity effects. However, its clinical application is restricted by challenges such as low solubility, poor bioavailability, and rapid metabolism. To overcome these limitations, researchers have developed a variety of nano-formulations for HNK delivery. These nano-formulations offer advantages such as enhanced solubility, improved bioavailability, extended circulation time, and targeted drug delivery. However, existing reviews of HNK primarily focus on its clinical and pharmacological features, leaving a gap in the comprehensive evaluation of HNK delivery systems based on nanotechnology. This paper aims to bridge this gap by comprehensively reviewing different types of nanomaterials used for HNK delivery over the past 15 years. These materials encompass vesicle delivery systems, nanoparticles, polymer micelles, nanogels, and various other nanocarriers. The paper details various HNK nano-delivery strategies and summarizes their latest applications, development prospects, and future challenges. To compile this review, we conducted an extensive search using keywords such as "honokiol", "nanotechnology", and "drug delivery system" on reputable databases, including PubMed, Scopus, and Web of Science, covering the period from 2008 to 2023. Through this search, we identified and selected approximately 90 articles that met our specific criteria.

Recent applications of phase-change materials in tumor therapy and theranostics

Phase-change materials (PCMs) are a type of special material which can store and release a large amount of thermal energy without any significant temperature change. They are emerging in recent years as a promising functional material in tumor therapy and theranostics due to their accurate responses to the temperature variations, biocompatibility and low toxicity. In this review, we will introduce the main types of PCMs and their desirable physiochemical properties for biomedical applications, and highlight the recent progress of PCM's applications in the modulated release of antitumor drugs, with special attentions paid to various ways to initiate temperature-dependent phase change, the concomitant thermal therapy and its combination with or activation of other therapies, particularly unconventional therapies. We will also summarize PCM's recent applications in tumor theranostics, where both drugs and imaging probes are delivered by PCMs for controlled drug release and imaging-guided therapy. Finally, the future perspectives and potential limitations of harnessing PCMs in tumor therapy will be discussed.

Phospholipid-mimicking block, graft, and block-graft copolymers for phase-transition microbubbles as ultrasound contrast agents

Background: Lipid and polymer microbubbles (MBs) are widely used as ultrasound contrast agents in clinical diagnosis, and possess great potential in ultrasound-mediated therapy due to their drug loading function. However, overcoming the limitations of stability and echo enhancement of MBs are still a considerable challenge.

Methods: A series novel block, graft and block-graft copolymers was proposed and prepared in this work, and these copolymers were used as shells to encapsulate perfluoropentane as ultrasound contrast agents. First, block, graft and block-graft copolymers with different topological structures were prepared. Then, these copolymers were prepared into block copolymer phase-transition MBs, graft copolymer phase-transition MBs, and block-graft copolymer phase-transition MBs, respectively. Finally, the dexamethasone was used for drug-loaded phase-transition microbubbles model to explore the potential of theranostic microbubbles.

Results: Finally, these three resulting copolymer MBs with average size of 4–5 μm exhibited well enhancement of ultrasound imaging under the influence of different frequencies and mechanical index, and they exhibited a longer contrast-enhanced ultrasound imaging time and higher resistance to mechanical index compared with SonoVue in vitro and in vivo. In vitro drug release results also showed that these copolymer MBs could encapsulate dexamethasone drugs, and the drug release could be enhanced by ultrasonic triggering. These copolymer MBs were therapeutic MBs for targeted triggering drug release.

Conclusion: Therefore, the feasibility of block, graft, and block-graft copolymers as ultrasonic contrast agents was verified, and their ultrasonic enhancement performance in vitro and in vivo was compared. The ultrasound contrast agents developed in this work have excellent development potential in comprehensive diagnosis and treatment.

Alleviation of cardiac fibrosis using acellular peritoneal matrix-loaded pirfenidone nanodroplets after myocardial infarction in rats

Myocardial fibrosis (MF) in the remote myocardium is a feature at the micoscopic level of pathological remodeling after myocardial infarction (MI). Although pirfenidone (PFD), an antifibrotic agent, is commonly used to inhibit fibrosis in multiple organs, its clinical use is limited because of the high doses required for favorable therapeutic outcomes and various side effects. Nanodrug technology has allowed for delayed quantitative drug release and reduced the amount of medication required, improving the treatment strategy for MF. In this study, we investigated the possible therapeutic effect of peritoneal matrix-loaded pirfenidone nanodroplets (NDs) on MI fibrosis. The results showed that the Perfluoropentane-Pirfenidone@Nanodroplets-Polyethylene glycol 2000 (PFP-PFD@NDs-PEG) described in this study was successfully synthesized and demonstrated a high potential for the targeted treatment of MI. The total duration of pirfenidone release from PFP-PFD@NDs-PEG was increased by loading it into an acellular peritoneal matrix (APM). Additionally, pirfenidone inhibited the transformation of cardiac fibroblasts into cardiac myofibroblasts in vitro and reduced the synthesis and secretion of collagen I and collagen III by cardiac myofibroblasts. The combination of the APM with pirfenidone nanodroplets achieved a slow drug release and showed excellent therapeutic effects on fibrosis in MI rats. Our study confirmed the feasibility and synergistic effectiveness of the APM combined with pirfenidone nanodroplets in the treatment of fibrosis in MI rats. Moreover, our technique offers a great potential for applying nanomedicine in other biomedical fields.

Research progress on nanotechnology for delivery of active ingredients from traditional Chinese medicines

There is growing acceptance of traditional Chinese medicines (TCMs) as potential sources of clinical agents based on the demonstrated efficacies of numerous bioactive compounds first identified in TCM extracts, such as paclitaxel, camptothecin, and artemisinin. However, there are several challenges to achieving the full clinical potential of many TCMs, particularly the generally high hydrophobicity and low bioavailability. Recently, however, numerous studies have attempted to circumvent the limited in vivo activity and systemic toxicity of TCM ingredients by incorporation into nanoparticle-based delivery systems. Many of these formulations demonstrate improved bioavailability, enhanced tissue targeting, and greater in vivo stability compared to the native compound. This review summarizes nanoformulations of the most promising and extensively studied TCM compounds to provide a reference for further research. Combining these natural compounds with nanotechnology-based delivery systems may further improve the clinical utility of these agents, in turn leading to more intensive research on traditional medicinal compounds.

3D-printed microfluidic chip for the preparation of glycyrrhetinic acid-loaded ethanolic liposomes

18-α-Glycyrrhetinic acid (GA) is a bioactive compound extracted from licorice that exhibits many biological and pharmacological effects such as anti-inflammatory and antioxidant activities on the skin. However, its lipophilic nature results in poor bioavailability that limits clinical applications. Liposomes, presenting the ability to carry both hydrophobic and hydrophilic payloads and a good cytocompatibility, are effective to overcome this barrier. Furthermore, the addition of permeation enhancers such as ethanol into liposomal formulations helps the diffusion of these systems through the skin barrier. Here, we aimed to formulate GA-loaded ethanolic liposomes, using a natural soybean lecithin via a microfluidic approach. Using a fused deposition modeling (FDM) 3D printer we customized a microfluidic chip, and manufactured vesicles that presented spherical shape with a size of 202 ± 5.2 nm, a narrow size distribution and a good stability over a period of 30 days. After reaching a drug encapsulation efficiency of 63.15 ± 2.2%, liposomes were evaluated for their cytocompatibility and skin permeation potentiality after hydrogelation using xanthan gum. The in vitro release and permeation studies were performed using Franz diffusion cells comparing two different media and three synthetic membranes including a polymeric skin-mimicking membrane. The selected formulation presented no cytotoxicity and an increased permeation compared to GA saturated hydrogel. It could perform therapeutically better effects than conventional formulations containing free GA, as prolonged and controlled release topical dosage forms, which may lead to improved efficiency and better patient compliance.

Poly(lactide-co-glycolide) grafted hyaluronic acid-based electrospun fibrous hemostatic fragments as a sustainable anti-infection and immunoregulation material

Poly(lactide-co-glycolide) (PLGA) copolymers are promising synthetic materials in the biomedical field. However, in wound management, their hydrophobic properties limit their further application because of their poor adhesion to the surface of moist wounds. Furthermore, the lack of hemostatic materials with sustainable anti-infection and immunoregulation functions remains a highly significant clinical problem, as commercially available hemostatic products, such as Arista™, Celox™ and QuikClot™, do not have sufficient infection prevention and immunoregulation properties. Herein, we employ electrospinning, ammonia dissociation and surface grafting techniques to develop a series of PLGA-based hemostatic materials, including a PLGA electrospun fibrous membrane, PLGA-NH2 fibrous particles and PLGA-hyaluronic acid fibrous fragments (PLGA-HA FFs). Notably, we load azithromycin on the PLGA-HA FFs to endow them with anti-infection and immunoregulation properties. The hemostatic mechanism analysis demonstrates that the PLGA-HA FFs show superior hemostasis performance compared to traditional gauzes. The results show that the PLGA-HA FFs can act as a versatile platform with high encapsulation of azithromycin (83.03% ± 2.81%) and rapid hemostasis (28 ± 2 s) as well as prominent cytocompatibility towards L929 cells, RAW 264.7 cells and red blood cells. We believe that the current research proposes a possible strategy to synthesize materials that achieve not only safe and effective hemostasis, but also have anti-infection and immunoregulation properties for the development of further hemostatic products.

Construction of CNA35 Collagen-Targeted Phase-Changeable Nanoagents for Low-Intensity Focused Ultrasound-Triggered Ultrasound Molecular Imaging of Myocardial Fibrosis in Rabbits

Myocardial fibrosis plays an important role in the development of heart failure and malignant arrhythmia, which potentially increases the incidence of sudden cardiac death. Therefore, early detection of myocardial fibrosis is of great significance for evaluating the prognosis of patients and formulating appropriate treatment strategies. Late gadolinium-enhanced magnetic resonance imaging is considered as the currently effective strategy for noninvasive detection of myocardial fibrosis, but it still suffers from some critical issues. In this work, multifunctional CNA35-labeled perfluoropentane nanoparticles (CNA35-PFP NPs) have been elaborately designed and constructed for molecular imaging of fibrotic myocardium based on ultrasound imaging. These as-constructed CNA35-PFP NPs are intravenously infused into rabbit circulation with an animal model of myocardial infarction. Especially, these targeted CNA35-PFP NPs with nanoscale size could efficiently pass through the endothelial cell gap and adhere to the surface of fibroblasts in the fibrotic myocardium. Importantly, followed by low-intensity focused ultrasound irradiation on the myocardium, these intriguing CNA35-PFP NPs could transform from liquid into gaseous microbubbles, which further significantly enhanced the ultrasound contrast in the fibrotic area, facilitating the detection by diagnostic ultrasound imaging. Therefore, this work provides a desirable noninvasive, economical, and real-time imaging technique for the assessment of cardiac fibrosis with diagnostic ultrasound based on the rational design of liquid-to-gas phase-changeable nanoplatforms.

Ultrasound-triggered perfluorocarbon-derived nanobombs for targeted therapies of rheumatoid arthritis

The targeted US-triggered PFC-based “nanobombs” with US used to treat the RA in this work would offer a new treatment strategy and have a great potential for the application in the areas of theranostic agent and nanomedicine treatment.

Iron oxide nanoparticles for targeted imaging of liver tumors with ultralow hepatotoxicity

Even though iron oxide (Fe₃O₄) nanoparticles are promising materials for magnetic resonance imaging (MRI) contrast agents, their biocompatibility and targeting efficacy still need to be improved. Herein, we modified glycyrrhetinic acid (GA) groups on Fe₃O₄ nanoparticles (Fe₃O₄@cGlu-GA) for liver tumor-targeted imaging. To evaluate the biocompatibility of these nanoparticles, we studied their cytotoxicity, hemolysis, and hepatotoxicity. We measured the uptake of Fe₃O₄@cGlu-GA nanoparticles in normal and liver tumor cells, then we investigated the specificity of Fe₃O₄@cGlu-GA nanoparticles in mouse models bearing subcutaneous and orthotopic liver tumors. With good biocompatibility and targeting efficacy both in vitro and in vivo, the Fe₃O₄@cGlu-GA nanoparticles are promising MRI contrast agents with ultralow hepatotoxicity and show great improvement on existing Fe₃O₄-based nanoparticles.