Engineering Ferroptosis Inhibitors as Inhalable Nanomedicines for the Highly Efficient Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) refers to chronic progressive fibrotic interstitial pneumonia. It is called a "tumor-like disease" and cannot be cured using existing clinical drugs. Therefore, new treatment options are urgently needed. Studies have proven that ferroptosis is closely related to the development of IPF, and ferroptosis inhibitors can slow down the occurrence of IPF by chelating iron or reducing lipid peroxidation. For example, the ferroptosis inhibitor deferoxamine (DFO) was used to treat a mouse model of pulmonary fibrosis, and DFO successfully reversed the IPF phenotype and increased the survival rate of mice from 50% to 90%. Given this, we perceive that the treatment of IPF by delivering ferroptosis inhibitors is a promising option. However, the delivery of ferroptosis inhibitors faces two bottlenecks: low solubility and targeting. For one thing, we consider preparing ferroptosis inhibitors into nanomedicines to improve solubility. For another thing, we propose to deliver nanomedicines through pulmonary drug-delivery system (PDDS) to improve targeting. Compared with oral or injection administration, PDDS can achieve better delivery and accumulation in the lung, while reducing the systemic exposure of the drug, and is an efficient and safe drug-delivery method. In this paper, three possible nanomedicines for PDDS and the preparation methods thereof are proposed to deliver ferroptosis inhibitors for the treatment of IPF. Proper administration devices and challenges in future applications are also discussed. In general, this perspective proposes a promising strategy for the treatment of IPF based on inhalable nanomedicines carrying ferroptosis inhibitors, which can inspire new ideas in the field of drug development and therapy of IPF.

Demonstrating Biological Fate of Nanoparticle-Loaded Dissolving Microneedles with Aggregation-Caused Quenching Probes: Influence of Application Sites

Integrating dissolving microneedles (DMNs) and nanocarriers (NC) holds great potential in transdermal drug delivery because it can simultaneously overcome the stratum corneum barrier and achieve efficient and controlled drug delivery. However, different skin sites with different thicknesses and compositions can affect the transdermal diffusion of NC-loaded DMNs. There are few reports on the biological fate (especially transdermal diffusion) of NC-loaded DMNs, and inaccurate bioimaging information of intact NC limits the accurate understanding of the in vivo fate of NC-loaded DMNs. The aggregation-caused quenching (ACQ) probes P4 emitted intense fluorescence signals in intact NC while quenched after the degradation of NC, had been demonstrated the feasibility of label intact NC. In this study, P4 was loaded in solid lipid nanoparticles (SLNs), and further encapsulated into DMNs, to track the transdermal diffusion of SLNs delivered at different skin sites. The results showed that SLNs had excellent stability after being loaded into DMNs with no significant changes in morphology and fluorescence properties. The in vivo live and ex vivo imaging showed that the transdermal diffusion rate of NC-loaded DMNs was positively correlated with skin thickness, with the order ear > abdomen > back. In conclusion, this study confirmed the site-dependency of transdermal diffusion in NC-loaded DMNs.

Explicating the publication paradigm by bibliometric approaches: A case of interplay between nanoscience and ferroptosis

BACKGROUND

Ferroptosis has been widely investigated as an emerging drug target, while its combination with nanoscience provides bourgeoning application prospects. The development of ferroptosis regulating nanomedicines have attracted worldwide attentions in recent years. It would be meaningful to describe the relevant publication paradigm.

METHODS

Herein, a bibliometric analysis was performed using the database of Web of Science Core Collection to clarify the publication paradigm. The development of related publications in the last 6 years was described, and the revolutionary trends were figured out. Ultimately, the possible future exploration directions were proposed.

RESULTS

The bibliometric analysis of 327 documents of interest indicated that the main research focus was in multiple fields including Materials science, Science & technology, Chemistry, and Pharmacology & pharmacy. With widely cooperation and strong funding, the researchers from Chinese organizations contributed most of publications, followed with United States and Australia. Cocitation analysis revealed that several original papers reported the key molecular mechanisms of ferroptosis were considered as the foundation for subsequent studies, and some nanomedicines-related documents were taken as examples and discussed. Mining results showed that the mechanism evaluation of ferroptosis regulation therapy for cancer treatment was the hotspot. Then, several possible future explorations of ferroptosis-related nanoscience were presented and discussed.

CONCLUSIONS

The bibliometric profile of nanoscience-ferroptosis research was analyzed in detail. We believe that the bibliometric analysis could act as a robust method for explicating the publication paradigm as a certain field.

The Necessity to Investigate In Vivo Fate of Nanoparticle-Loaded Dissolving Microneedles

Transdermal drug delivery systems are rapidly gaining prominence and have found widespread application in the treatment of numerous diseases. However, they encounter the challenge of a low transdermal absorption rate. Microneedles can overcome the stratum corneum barrier to enhance the transdermal absorption rate. Among various types of microneedles, nanoparticle-loaded dissolving microneedles (DMNs) present a unique combination of advantages, leveraging the strengths of DMNs (high payload, good mechanical properties, and easy fabrication) and nanocarriers (satisfactory solubilization capacity and a controlled release profile). Consequently, they hold considerable clinical application potential in the precision medicine era. Despite this promise, no nanoparticle-loaded DMN products have been approved thus far. The lack of understanding regarding their in vivo fate represents a critical bottleneck impeding the clinical translation of relevant products. This review aims to elucidate the current research status of the in vivo fate of nanoparticle-loaded DMNs and elaborate the necessity to investigate the in vivo fate of nanoparticle-loaded DMNs from diverse aspects. Furthermore, it offers insights into potential entry points for research into the in vivo fate of nanoparticle-loaded DMNs, aiming to foster further advancements in this field.

Research on nanosciences involvement in pharmaceutical education should be reinforced

Inclusion of nanoscience in pharmaceutical education should be reinforced, in order to match the demand of current pharmaceutical talent cultivation.

Construction of Cisplatin-18-Crown-6 Complexes Through Supramolecular Chemistry to Improve Solubility, Stability, and Antitumor Activity

Cisplatin (DDP), a platinum-chelated compound renowned for its antitumor activity, is often utilized in cancer therapy. However, its real-world clinical efficacy is compromised by poor solubility and low stability, which impedes wider clinical application. Our study aimed to address these limitations of DDP through host-guest supramolecular chemistry approaches. We explored the potential of 18-crown-6 as the host molecule to solubilize and stabilize DDP, the guest molecule. Utilizing techniques such as UV-visible spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and molecular docking, we conducted a comprehensive analysis on the physical state and inclusion mode of the DDP@18-crown-6 complex. Phase solubility studies and Job's plot confirmed that the DDP@18-crown-6 complex significantly enhanced the aqueous solubility of DDP, with an optimal 1:1 binding ratio. Stability analyses revealed that this complex markedly improved the stability of DDP in pure water. Meanwhile, the stabilization effects of DDP@18-crown-6 were remarkably elevated when combined with 0.9% sodium chloride. In vitro antitumor assays in A549 cell lines demonstrated that the DDP@18-crown-6 complex outperformed raw DDP in cytotoxicity, showing a significantly lower IC50 value. This research offered a promising strategy for DDP solubilization and stabilization, facilitating its anticancer therapeutic efficacy.

Encapsulating taurine into liposomes: A promising therapeutic for liver fibrosis

We summarize the mechanism by which taurine (Tau) inhibits autophagy and induces iron apoptosis in hepatic stellate cells. Tau interacts with autophagy regulates multifunctional proteins, microtubule-associated protein 1 light chain 3 Beta, and autophagy-related gene 5 to inhibit autophagy, binds to ferritin heavy chain 1 and nuclear receptor coactivator 4 to trigger ferritin autophagy, and interacts with glutathione peroxidase 4 to promote iron apoptosis. There is a solid rationale for developing Tau-based therapies targeting autophagy and ferroptosis regulation. From a pharmaceutical point of view, there are certain requirements for Tau protein delivery systems, such as loading efficiency, stability, and targeting. Nanomaterials should also contain a hydrophilic motif similar to Tau to optimize loading efficiency. Since Tau is a hydrophilic molecule with high water solubility, liposomes, micelles, and amphiphilic polymer nanoparticles may represent a superior choice. The nanostructure of the liposome includes a water region and a lipid membrane to sequester hydrophilic and hydrophobic drugs, respectively, whereas Tau is expected to be loaded into the water region. In addition, a representative method of actively targeting hematopoietic stem cells is introduced. A Tau-based method for the treatment of liver fibrosis is proposed based on the formulation of common liposomes (lecithin plus cholesterol).

Three Different Interaction Patterns between MCM-41 and Proteins

As one of the most studied mesoporous silica nanoparticles (MSNs) in drug delivery systems, Mobil Composition of Matter No. 41 (MCM-41) possesses unique properties including perfect channel architecture, excellent load capacity, and good biocompatibility. However, the applications of MCM-41 nanoparticles in drug delivery have not yet been industrialized, due to the interaction between MCM-41 and biomolecules (especially proteins) that affect their in vivo behaviors after dosing. To investigate the interactions between MCM-41 and proteins, this study selected bovine serum albumin (BSA), lysozyme (Lyso), and bovine hemoglobin (BHb) as model proteins and characterized the ultraviolet-visible, fluorescence, circular dichroism spectra and the protein adsorption of MCM-41-protein complex. The UV-Vis spectra exhibited the different absorption increment degrees of three proteins. The fluorescence spectra showed that the fluorescence intensity of proteins changed by different trends. The CD spectra indicated that the secondary structure changes were ranked as BSA > Lyso > BHb, which is consistent with the protein’s adsorption capability on MCM-41. It was shown that there were three different patterns of MCM-41-proteins interactions. The hydrophilic and low-charged BSA followed the strong interaction pattern, the hydrophilic but heavily charged Lyso followed the moderate interaction pattern, and the hydrophobic BHb followed the weak interaction pattern. Different interaction patterns would lead to different effects on the structural properties of proteins, the surface chemistry of MCM-41, and the absorption capability of proteins on MCM-41. We believe our study will provide a better insight into the application of MCM-41 nanoparticles in drug delivery systems.

Mapping the intersection of nanotechnology and SARS-CoV-2/COVID-19: A bibliometric analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has imposed great medical and economic burdens on human society, and nanotechnology is a promising technique for managing the ongoing COVID-19 pandemic. To drive further studies on anti-COVID-19 nanotechnology, this paper provides an analysis, from a bibliometric perspective, of the intersection of nanotechnology and SARS-CoV-2/COVID-19.

METHODS

We analyzed the 2585 publications on nanotechnology and SARS-CoV-2/COVID-19 included in the Web of Science Core Collection from January 2019 to March 2022 to determine the bibliometric landscape. The basic bibliometric characteristics are summarized in this article.

RESULTS

Our bibliometric analysis revealed that the intersection between nanotechnology and SARS-CoV-2/COVID-19 is a cutting-edge field in the science community and that the related studies were multidisciplinary in nature. Studies on the structural basis of SARS-CoV-2, SARS-CoV-2 detection assays, and mRNA vaccines against COVID-19 provided the development foundation for this field.

CONCLUSIONS

The current research focuses are the development of nanomaterial-based vaccines and SARS-CoV-2 detection methods, and the design of nanomedicines carrying SARS-CoV-2 inhibitors is a relatively burgeoning frontier. In summary, this bibliometric analysis of the intersection of nanotechnology and SARS-CoV-2/COVID-19 highlights the current research focuses of this field to inspire future studies on anti-COVID-19 nanotechnologies.

Utilization of Lyotropic Liquid Crystalline Gels for Chronic Wound Management

Management of chronic wounds is becoming a serious health problem worldwide. To treat chronic wounds, a suitable healing environment and sustained delivery of growth factors must be guaranteed. Different therapies have been applied for the treatment of chronic wounds such as debridement and photodynamic therapy. Among them, growth factors are widely used therapeutic drugs. However, at present, growth factor delivery systems cannot meet the demand of clinical practice; therefore new methods should be developed to meet the emerging need. For this reason, researchers have tried to modify hydrogels through some methods such as chemical synthesis and molecule modifications to enhance their properties. However, there are still a large number of limitations in practical use like byproduct problems, difficulty to industrialize, and instability of growth factor. Moreover, applications of new materials like lyotropic liquid crystalline (LLC) on chronic wounds have emerged as a new trend. The structure of LLC is endowed with many excellent properties including low cost, ordered structure, and excellent loading efficiency. LLC can provide a moist local environment for the wound, and its lattice structure can embed the growth factors in the water channel. Growth factor is released from the high-concentration carrier to the low-concentration release medium, which can be precisely regulated. Therefore, it can provide sustained and stable delivery of growth factors as well as a suitable healing environment for wounds, which is a promising candidate for chronic wound healing and has a broad prospective application. In conclusion, more reliable and applicable drug delivery systems should be designed and tested to improve the therapy and management of chronic wounds.

High mRNA Expression of 24 Dehydrocholesterol Reductase (DHCR24) in the Treatment of Doxorubicin-Induced Heart Failure in Rats

OBJECTIVE

The objective of this study was to explore the possibility of treating heart failure in rats by delivering mRNA of 24-dehydrocholesterol reductase (DHCR24) into the body through lipid nanoparticles (LNPs).

METHODS

We established a heart failure rat model using doxorubicin. The experiment was divided into blank, model, mRNA stock solution cardiac injection, mRNA stock solution intravenous injection, LNP-mRNA stock solution cardiac injection, and LNP-mRNA stock solution intravenous injection groups. We directly injected DHCR24-mRNA or LNP-DHCR24-mRNA into the myocardium in three regions through an insulin needle passing through the intercostal space under the guidance of B-ultrasound. We recorded the mortality rate, body weight, 6-min walk test return times, and organ weight of rats after administration and detected the cardiac structure and function using B-ultrasound and transmission electron microscopy (TEM). Additionally, we tested for HE staining; PRDX2, Sirt3, and TRX1 protein expression; and IL-1 β, IL-10, VEGF, NT proBNP, and BNP cytokine concentrations.

RESULTS

Compared with the model group, the administration of DHCR24-mRNA significantly reduced mortality; decreased weight loss, the ratio of heart to tibia length, and spleen weight; and improved rat motility. The administration of DHCR24-mRNA can postpone the pathological morphological alterations of myocardial cells and reduce inflammatory infiltration. In terms of biochemistry, the administration of DHCR24-mRNA can increase the expression of the PRDX2, Sirt3, and TRX1 proteins; increase the concentrations of IL-10 and VEGF; and reduce the concentrations of IL-1β, NT proBNP, and BNP. The administration of DHCR24-mRNA can also delay the process of heart failure. The delivery and therapeutic effect of DHCR24-mRNA encapsulated in LNPs were better when compared to the other groups.

CONCLUSIONS

DHCR24-mRNA encapsulated in LNPs can be effectively administered to rats with heart failure and exhibits some curative effects.

The Effect of Sulfobetaine Coating in Inhibiting the Interaction between Lyotropic Liquid Crystalline Nanogels and Proteins

The injective lyotropic liquid crystalline nanogels (LLCNs) were widely used in drug delivery systems. But when administered in vivo, LLCNs exposed to the biological environment interact with proteins. Recently, it has been shown that nanoparticles coated with zwitterions can inhibit their interaction with proteins. Thus, in this study, the interaction between proteins and LLCNs coated with the zwitterionic material sulfobetaine (GLLCNs@HDSB) was investigated using bovine serum albumin (BSA) as a model protein. Interestingly, it was found that GLLCNs@HDSB at higher concentrations (≥0.8 mg/mL) could block its interaction with BSA, but not at lower concentrations (<0.8 mg/mL), according to the results of ultraviolet, fluorescence, and circular dichroism spectra. In the ultraviolet spectra, the absorbance of GLLCNs@HDSB (0.8 mg/mL) was 1.9 times higher than that without the sulfobetaine coating (GLLCNs) after incubation with protein; the fluorescence quenching intensity of GLLCNs@HDSB was conversely larger than that of the GLLCNs; in circular dichroism spectra, the ellipticity value of GLLCNs@HDSB was significantly smaller than that of the GLLCNs, and the change in GLLCNs@HDSB was 10 times higher than that of the GLLCNs. Generally, nanoparticles coated with sulfobetaine can inhibit their interaction with proteins, but in this study, LLCNs showed a concentration-dependent inhibitory effect. It could be inferred that in contrast to the surface of nanoparticles covered with sulfobetaine in other cases, the sulfobetaine in this study interacted with the LLCNs and was partially inserted into the hydrophobic region of the LLCNs. In conclusion, this study suggests that coating-modified nanoparticles do not necessarily avoid interacting with proteins, and we should also study coating-modified nanoparticles interacting with proteins both in vitro and in vivo. In the future, finding a coating material to completely inhibit the interaction between LLCNs and proteins will generate a great impetus to promote the clinical transformation of LLCNs.

Overcoming the Low-Stability Bottleneck in the Clinical Translation of Liposomal Pressurized Metered-Dose Inhalers: A Shell Stabilization Strategy Inspired by Biomineralization

Currently, several types of inhalable liposomes have been developed. Among them, liposomal pressurized metered-dose inhalers (pMDIs) have gained much attention due to their cost-effectiveness, patient compliance, and accurate dosages. However, the clinical application of liposomal pMDIs has been hindered by the low stability, i.e., the tendency of the aggregation of the liposome lipid bilayer in hydrophobic propellant medium and brittleness under high mechanical forces. Biomineralization is an evolutionary mechanism that organisms use to resist harsh external environments in nature, providing mechanical support and protection effects. Inspired by such a concept, this paper proposes a shell stabilization strategy (SSS) to solve the problem of the low stability of liposomal pMDIs. Depending on the shell material used, the SSS can be classified into biomineralization (biomineralized using calcium, silicon, manganese, titanium, gadolinium, etc.) biomineralization-like (composite with protein), and layer-by-layer (LbL) assembly (multiple shells structured with diverse materials). This work evaluated the potential of this strategy by reviewing studies on the formation of shells deposited on liposomes or similar structures. It also covered useful synthesis strategies and active molecules/functional groups for modification. We aimed to put forward new insights to promote the stability of liposomal pMDIs and shed some light on the clinical translation of relevant products.

Nano-Formulations for Pulmonary Delivery: Past, Present, and Future Perspectives

With the development of nanotechnology and confronting the problems of traditional pharmaceutical formulations in treating lung diseases, inhalable nano-formulations have attracted interest. Inhalable nano-formulations for treating lung diseases allow for precise pulmonary drug delivery, overcoming physiological barriers, improving aerosol lung deposition rates, and increasing drug bioavailability. They are expected to solve the difficulties faced in treating lung diseases. However, limited success has been recorded in the industrialization translation of inhalable nano-formulations. Only one relevant product has been approved by the FDA to date, suggesting that there are still many issues to be resolved in the clinical application of inhalable nano-formulations. These systems are characterized by a dependence on inhalation devices, while the adaptability of device formulation is still inconclusive, which is the most important issue impeding translational research. In this review, we categorized various inhalable nano-formulations, summarized the advantages of inhalable nano-formulations over conventional inhalation formulations, and listed the inhalable nano-formulations undergoing clinical studies. We focused on the influence of inhalation devices on nano-formulations and analyzed their adaptability. After extensive analysis of the drug delivery mechanisms, technical processes, and limitations of different inhalation devices, we concluded that vibrating mesh nebulizers might be most suitable for delivering inhalable nano-formulations, and related examples were introduced to validate our view. Finally, we presented the challenges and outlook for future development. We anticipate providing an informative reference for the field.

Aggregation-Caused Quenching Dyes as Potent Tools to Track the Integrity of Antitumor Nanocarriers: A Mini-Review

Cancer has become one of the major causes of death worldwide. Chemotherapy remains a cornerstone of cancer treatment. To enhance the tumor-targeting efficiency of chemotherapy agents, pharmaceutical scientists have developed nanocarriers. However, the in vivo structural integrity and dynamic changes in nanocarriers after administration are not well understood, which may significantly impact their tumor-targeting abilities. In this paper, we propose the use of environmentally responsive fluorescent probes to track the integrity of antitumor nanocarriers. We compare three main types of dyes: fluorescence resonance energy transfer (FRET) dyes, aggregation-induced emission (AIE) dyes, and aggregation-caused quenching (ACQ) dyes. Among them, ACQ dyes, possessing sensitive water-quenching properties and easily detected "on-off" switching behavior, are regarded as the most promising choice. We believe that ACQ dyes are suitable for investigating the in vivo fate of antitumor nanocarriers and can aid in designing improved nanoformulations for chemotherapy agents.

A Pilot Study Exploiting the Industrialization Potential of Solid Lipid Nanoparticle-Based Metered-Dose Inhalers

BACKGROUND

Delivery of inhalable nanoparticles through metered-dose inhalers (MDI) is a promising approach to treat lung disease such as asthma and chronic obstructive pulmonary disease. Nanocoating of the inhalable nanoparticles helps in stability and cellular uptake enhancement but complicates the production process. Thus, it is meaningful to accelerate the translation process of MDI encapsulating inhalable nanoparticles with nanocoating structure.

METHODS

In this study, solid lipid nanoparticles (SLN) are selected as a model inhalable nanoparticle system. An established reverse microemulsion strategy was utilized to explore the industrialization potential of SLN-based MDI. Three categories of nanocoating with the functions of stabilization (by Poloxamer 188, encoded as SLN(0)), cellular uptake enhancement (by cetyltrimethylammonium bromide, encoded as SLN(+)), and targetability (by hyaluronic acid, encoded as SLN(-)) were constructed upon SLN, whose particle size distribution and zeta-potential were characterized. Subsequently, SLN were loaded into MDI, and evaluated for the processing reliability, physicochemical nature, formulation stability, and biocompatibility.

RESULTS

The results elucidated that three types of SLN-based MDI were successfully fabricated with good reproducibility and stability. Regarding safety, SLN(0) and SLN(-) showed negligible cytotoxicity on cellular level.

CONCLUSIONS

This work serves as a pilot study for the scale-up of SLN-based MDI, and could be useful for the future development of inhalable nanoparticles.

Editorial on Special Issue "Design and Optimization of Pharmaceutical Gels"

The efficacy of many bioactive agents, including drugs, food supplements, and vaccines, is limited because of their poor chemical stability, low water solubility, and low oral bioavailability [...].

Mechanisms and therapeutic targets of ferroptosis: Implications for nanomedicine design

Ferroptosis is a nonapoptotic form of cell death and differs considerably from the well-known forms of cell death in terms of cell morphology, genetics, and biochemistry. The three primary pathways for cell ferroptosis are system Xc-/glutathione peroxidase 4 (GPX4), lipid metabolism, and ferric metabolism. Since the discovery of ferroptosis, mounting evidence has revealed its critical regulatory role in several diseases, especially as a novel potential target for cancer therapy, thereby attracting increasing attention in the fields of tumor biology and anti-tumor therapy. Accordingly, broad prospects exist for identifying ferroptosis as a potential therapeutic target. In this review, we aimed to systematically summarize the activation and defense mechanisms of ferroptosis, highlight the therapeutic targets, and discuss the design of nanomedicines for ferroptosis regulation. In addition, we opted to present the advantages and disadvantages of current ferroptosis research and provide an optimistic vision of future directions in related fields. Overall, we aim to provide new ideas for further ferroptosis research and inspire new strategies for disease diagnosis and treatment.

Photodynamic therapy for cancer: mechanisms, photosensitizers, nanocarriers, and clinical studies

Photodynamic therapy (PDT) is a temporally and spatially precisely controllable, noninvasive, and potentially highly efficient method of phototherapy. The three components of PDT primarily include photosensitizers, oxygen, and light. PDT employs specific wavelengths of light to active photosensitizers at the tumor site, generating reactive oxygen species that are fatal to tumor cells. Nevertheless, traditional photosensitizers have disadvantages such as poor water solubility, severe oxygen-dependency, and low targetability, and the light is difficult to penetrate the deep tumor tissue, which remains the toughest task in the application of PDT in the clinic. Here, we systematically summarize the development and the molecular mechanisms of photosensitizers, and the challenges of PDT in tumor management, highlighting the advantages of nanocarriers-based PDT against cancer. The development of third generation photosensitizers has opened up new horizons in PDT, and the cooperation between nanocarriers and PDT has attained satisfactory achievements. Finally, the clinical studies of PDT are discussed. Overall, we present an overview and our perspective of PDT in the field of tumor management, and we believe this work will provide a new insight into tumor-based PDT.