A drug-specific nanocarrier design for efficient anticancer therapy

Pulmonary delivery of dual-targeted nanoparticles improves tumor accumulation and cancer cell targeting by restricting macrophage interception in orthotopic lung tumors

Despite the recognized potential of inhaled nanomedicines to enhance and sustain local drug concentrations for lung cancer treatment, the influence of macrophage uptake on targeted nanoparticle delivery to and within tumors remains unclear. Here, we developed three ligand-coated nanoparticles for pulmonary delivery in lung cancer therapy: phenylboronic acid-modified nanoparticles (PBA-NPs), PBA combined with folic acid (FA-PBA-NPs), and PBA with mannose (MAN-PBA-NPs). In vitro, MAN-PBA-NPs were preferentially internalized by macrophages, whereas FA-PBA-NPs exhibited superior uptake by cancer cells compared to macrophages. Following intratracheal instillation into mice with orthotopic Lewis lung carcinoma tumors, all three nanoparticles showed similar lung retention. However, MAN-PBA-NPs were more prone to interception by lung macrophages, which limited their accumulation in tumor tissues. In contrast, both PBA-NPs and FA-PBA-NPs achieved comparable high tumor accumulation (∼11.3% of the dose). Furthermore, FA-PBA-NPs were internalized by ∼30% of cancer cells, significantly more than the 10-18% seen with PBA-NPs or MAN-PBA-NPs. Additionally, FA-PBA-NPs loaded with icaritin effectively inhibited the Wnt/β-catenin pathway, resulting in superior anti-tumor efficacy through targeted cancer cell delivery. Overall, FA-PBA-NPs demonstrated advantageous competitive uptake kinetics by cancer cells compared to macrophages, enhancing tumor targeting and therapeutic outcomes.

Rational strategies for improving the efficiency of design and discovery of nanomedicines

The rise of rational strategies in nanomedicine development, such as high-throughput methods and computer-aided techniques, has led to a shift in the design and discovery patterns of nanomedicines from a trial-and-error mode to a rational mode. This transition facilitates the enhancement of efficiency in the preclinical discovery pipeline of nanomaterials, particularly in improving the hit rate of nanomaterials and the optimization efficiency of promising candidates. Herein, we describe a directed evolution mode of nanomedicines driven by data to accelerate the discovery of nanomaterials with high delivery efficiency. Computer-aided design strategies are introduced in detail as one of the cutting-edge directions for the development of nanomedicines. Ultimately, we look forward to expanding the tools for the rational design and discovery of nanomaterials using multidisciplinary approaches. Rational design strategies may potentially boost the delivery efficiency of next-generation nanomedicines.

Nanotechnology-assisted combination drug delivery: a progressive approach for the treatment of acute myeloid leukemia

Acute myeloid leukemia (AML), a heterogeneous hematopoietic cancer prevalent in adults, has been a leading cause of leukemia-associated deaths for decades. Despite advancements in understanding its pathology and pharmacological targets, therapeutic strategies have seen minimal change. The standard treatment, combining cytarabine and anthracycline, has persisted, accompanied by challenges such as pharmacokinetic issues and non-specific drug delivery, leading to severe side effects. Nanotechnology offers a promising solution through combination drug delivery. FDA-approved CPX351 (VYXEOS™) a liposomal formulation delivering doxorubicin and cytarabine, exemplifies enhanced therapeutic efficacy. Ongoing research explores various nanocarriers for delivering multiple bioactives, addressing drug targeting, pharmacokinetics and chemoresistance. This review highlights nanotechnology-based combination therapies for the effective management of AML, presenting a potential breakthrough in leukemia.

PepT1-targeted nanodrug based on co-assembly of anti-inflammatory peptide and immunosuppressant for combined treatment of acute and chronic DSS-induced ColitiS

Introduction

Inflammatory bowel disease (IBD), as a chronic and recurrent inflammatory bowel diseases with limited therapeutic outcomes, is characterized by immune disorders and intestinal barrier dysfunction. Currently, the most medications used to cure IBD in clinic just temporarily induce and maintain remission with poor response rates and limited outcomes. Therefore, it is urgently necessary to develop an appropriate therapeutic candidate with preferable efficacy and less adverse reaction for curing IBD.

Methods

Five groups of mice were utilized: control that received saline, DSS group (mice received 2.5% DSS or 4% DSS), KPV group (mice received KPV), FK506 group (mice received FK506) and NPs groups (mice received NPs). The effect of NP on the inflammatory factors of macrophage was evaluated using CCK-8, quantitative polymerase chain reaction (PCR), Elisa and Western blot (WB). Immunofluorescent staining revealed the targeting relationship between NP and Petp-1. Immunohistochemistry staining showed the effect of NP on tight junction proteins. Moreover, in vivo animal experiments confirmed that NPs reduced inflammatory levels in IBD.

Results and Discussion

After administering with NPs, mice with DSS-induced acute or chronic colitis exhibited significant improvement in body weight, colon length, and disease activity index, decreased the level of the factors associated with oxidative stress (MPO, NO and ROS) and the inflammatory cytokines (TNF-α, IL-1β and IL-6), which implied that NPs could ameliorate murine colitis effectively. Furthermore, treating by NPs revealed a notable reduction of the expressions of CD68 and CD3, restoring the expression levels of tight junction proteins (Claudin-5, Occludin-1, and ZO-1) were significantly restored, surpassing those observed in the KPV and FK506 groups. which indicated that NPs can reduce inflammation and enhance epithelial barrier integrity by decreasing the infiltration of macrophages and T-lymphocytes. Collectively, those results demonstrated the effectively therapeutic outcome after using NPs in both acute and chronic colitis, suggesting that the newly co-assembled of NPs can be as a potential therapeutic candidate for colitis.

Apigenin: A Bioflavonoid with a Promising Role in Disease Prevention and Treatment

Apigenin is a powerful flavone compound found in numerous fruits and vegetables, and it offers numerous health-promoting benefits. Many studies have evidenced that this compound has a potential role as an anti-inflammatory and antioxidant compound, making it a promising candidate for reducing the risk of pathogenesis. It has also been found to positively affect various systems in the body, such as the respiratory, digestive, immune, and reproductive systems. Apigenin is effective in treating liver, lung, heart, kidney, neurological diseases, diabetes, and maintaining good oral and skin health. Multiple studies have reported that this compound is capable of suppressing various types of cancer through the induction of apoptosis and cell-cycle arrest, suppressing cell migration and invasion, reduction of inflammation, and inhibiting angiogenesis. When used in combination with other drugs, apigenin increases their efficacy, reduces the risk of side effects, and improves the response to chemotherapy. This review broadly analyzes apigenin's potential in disease management by modulating various biological activities. In addition, this review also described apigenin's interaction with other compounds or drugs and the potential role of nanoformulation in different pathogeneses. Further extensive research is needed to explore the mechanism of action, safety, and efficacy of this compound in disease prevention and treatment.

"Click" amphotericin B in prodrug nanoformulations for enhanced systemic fungemia treatment

Severe nephrotoxicity and infusion-related side effects pose significant obstacles to the clinical application of Amphotericin B (AmB) in life-threatening systemic fungal infections. In pursuit of a cost-effective and safe formulation, we have introduced multiple phenylboronic acid (PBA) moieties onto a linear dendritic telodendrimer (TD) scaffold, enabling effective AmB conjugation via boronate chemistry through a rapid, high yield, catalysis-free and dialysis-free "Click" drug loading process. Optimized AmB-TD prodrugs self-assemble into monodispersed micelles characterized by small particle sizes and neutral surface charges. AmB prodrugs sustain drug release in circulation, which is accelerated in response to the acidic pH and Reactive Oxygen Species (ROS) in the infection and inflammation. Prodrugs mitigate the AmB aggregation status, reduce cytotoxicity and hemolytic activity compared to Fungizone®, and demonstrate superior antifungal activity to AmBisome®. AmB-PEG5kBA4 has a comparable maximum tolerated dose (MTD) to AmBisome®, while over 20-fold increase than Fungizone®. A single dose of AmB-PEG5kBA4 demonstrates superior efficacy to Fungizone® and AmBisome® in treating systemic fungal infections in both immunocompetent and immunocompromised mice.

Telodendrimer functionalized hydrogel platform for sustained antibiotics release in infection control

Wound infection commonly causes delayed healing, especially in the setting of chronic wounds. Local release of antibiotics is considered a viable approach to treat chronic wounds. We have developed a versatile telodendrimer (TD) platform for efficient loading of charged antibiotic molecules via a combination of multivalent and synergistic charge and hydrophobic interactions. The conjugation of TD in biocompatible hydrogel allows for topical application to provide sustained antibiotic release. Notably, a drug loading capacity as high as 20 % of the drug-to-resin dry weight ratio can be achieved. The payload content (PC) and release profile of the various antibiotics can be optimized by fine-tuning TD density and valency in hydrogel based on the charge and hydrophobic features of the drug, e.g., polymyxin B (PMB), gentamycin (GM), and daptomycin (Dap), for effective infection control. We have shown that hydrogel with moderately reduced TD density demonstrates a more favorable release profile than hydrogel with higher TD density. Antibiotics loaded in TD hydrogel have comparable antimicrobial potency and reduced cytotoxicity compared to the free antibiotics due to a prolonged, controlled drug release profile. In a mouse model of skin and soft tissue infection, the subcutaneous administration of PMB-loaded TD hydrogel effectively eliminated the bacterial burden. Overall, these results suggest that engineerable TD hydrogels have great potential as a topical treatment to control infection for wound healing. STATEMENT OF SIGNIFICANCE: Wound infection causes a significant delay in the wound healing process, which results in a significant financial and resource burden to the healthcare system. PEGA-telodendrimer (TD) resin hydrogel is an innovative and versatile platform that can be fine-tuned to efficiently encapsulate different antibiotics by altering charged and hydrophobic structural moieties. Additionally, this platform is advantageous as the TD density in the resin can also be fine-tuned to provide the desired antibiotic payload release profile. Sustained antibiotics release through optimization of TD density provides a prolonged therapeutic window and reduces burst release-induced cytotoxicity compared to conventional antibiotics application. Studies in a preclinical mouse model of bacteria-induced skin and soft tissue infection demonstrated promising therapeutic efficacy as evidenced by effective infection control and prolonged antibacterial efficacy of antibiotics-loaded PEGA-TD resin. In conclusion, the PEGA-TD resin platform provides a highly customizable approach for effective antibiotics release with significant potential for topical application to treat various bacterial wound infections to promote wound healing.

Dendrimer‐Based Nanodrugs for Chemodynamic Therapy of Tumors

To realize precise tumor treatment, chemodynamic therapy (CDT) that utilizes metal element to trigger Fenton or Fenton‐like reaction to generate cytotoxic hydroxyl radicals in tumor region has been widely investigated. Recently, the dendrimers featured with abundant surface functional groups and excellent biocompatibility are regarded as promising carriers of metal elements for tumor delivery. Much effort has been devoted to design dendrimer‐based nanodrugs for CDT and CDT‐involved synergistic therapy of tumors. Herein, the recent advances in the construction of dendrimer‐based nanodrugs (in most cases, poly(amidoamine) dendrimers) for CDT, CDT/chemotherapy, CDT/phototherapy, CDT/gene therapy, or CDT‐involved multimodal therapy are reviewed. Furthermore, the future perspectives with regard to the development of dendrimer‐based nanodrugs for CDT‐involved tumor treatment are also briefly discussed.

Protein Nanotubes as Advanced Material Platforms and Delivery Systems

Protein nanotubes (PNTs) as state-of-the-art nanocarriers are promising for various potential applications both in the food and pharmaceutical industries. Derived from edible starting sources like α-lactalbumin, lysozyme, and ovalbumin, PNTs bear properties of biocompatibility and biodegradability. Their large specific surface area and hydrophobic core facilitate chemical modification and loading of bioactive substances, respectively. Moreover, their enhanced permeability and penetration ability across biological barriers such as intestinal mucus, extracellular matrix, and thrombus clot, make it promising platforms for health-related applications. Most importantly, their simple preparation processes enable large-scale production, supporting applications in the biomedical and nanotechnological fields. Understanding the self-assembly principles is crucial for controlling their morphology, size, and shape, and thus provides the ground to a multitude of applications. Here, the current state-of-the-art of PNTs including their building materials, physicochemical properties, and self-assembly mechanisms are comprehensively reviewed. The advantages and limitations, as well as challenges and prospects for their successful applications in biomaterial and pharmaceutical sectors are then discussed and highlighted. Potential cytotoxicity of PNTs and the need of regulations as critical factors for enabling in vivo applications are also highlighted. In the end, a brief summary and future prospects for PNTs as advanced platforms and delivery systems are included.

Engineering Nanotrap Hydrogel for Immune Modulation in Wound Healing

Imbalanced immune regulation leads to the abnormal wound healing process, e.g., chronic unhealing wound or hypertrophic scar formation. Thus, the attenuation of the overflowing inflammatory factors is a viable approach to maintain the homeostatic immune regulation to facilitate normal wound healing. A versatile telodendrimer (TD) nanotrap (NT) platform is developed for efficient biomolecular protein binding. The conjugation of TD NT in size-exclusive biocompatible hydrogel resin allows for topical application for cytokine scavenging. Fine-tuning the TD NT density/valency in hydrogel resin controls resin swelling, optimizes molecular diffusion, and improves cytokine capture for effective immune modulation. The hydrogel with reduced TD NT density allows for higher protein/cytokine adsorption capacity with faster kinetics, due to the reduced barrier of TD NT nano-assembly. The positively charged TD NT hydrogel exhibits superior removal of negatively charged proinflammatory cytokines from the lipopolysaccharide (LPS, a potent endotoxin) primed immune cell culture medium. The negatively charged TD NT hydrogel removes positively charged anti-inflammatory cytokines efficiently from cell culture medium. TD NT hydrogel effectively constrains the local inflammation induced by subcutaneous LPS injection in mice. These results indicate the great potential applications of the engineered TD NT hydrogel as topical immune modulatory treatments to attenuate local inflammation.

Molecular Docking-Guided Design on Glucose-Responsive Nanoparticles for Microneedle Fabrication and "Three-Meal-per-Day" Blood-Glucose Regulation

It was greatly significant, but difficult, to develop stimulus-responsive polymeric nanoparticles with efficient protein-loading and protein-delivering properties. Crucial obstacles were the ambiguous protein/nanoparticle-interacting mechanisms and the corresponding inefficient trial-and-error strategies, which brought large quantities of experiments in design and optimization. In this work, a molecular docking-guided universal "segment-functional group-polymer" process was proposed to simplify the previous laborious experimental step. The insulin-delivering glucose-responsive polymeric nanoparticles for diabetic treatments were taken as the examples. The molecular docking study obtained insights from the insulin/segment interactions. It was then experimentally confirmed in six functional groups for insulin-loading performances of their corresponding polymers. The optimization formulation was further proved effective in blood-glucose stabilization on the diabetic rats under the "three-meal-per-day" mode. It was believed that the molecular docking-guided designing process was promising in the protein-delivering field.

Baicalein Resensitizes Multidrug-Resistant Gram-Negative Pathogens to Doxycycline

As multidrug-resistant pathogens emerge and spread rapidly, novel antibiotics urgently need to be discovered. With a dwindling antibiotic pipeline, antibiotic adjuvants might be used to revitalize existing antibiotics. In recent decades, traditional Chinese medicine has occupied an essential position in adjuvants of antibiotics. This study found that baicalein potentiates doxycycline against multidrug-resistant Gram-negative pathogens. Mechanism studies have shown that baicalein causes membrane disruption by attaching to phospholipids on the Gram-negative bacterial cytoplasmic membrane and lipopolysaccharides on the outer membrane. This process facilitates the entry of doxycycline into bacteria. Through collaborative strategies, baicalein can also increase the production of reactive oxygen species and inhibit the activities of multidrug efflux pumps and biofilm formation to potentiate antibiotic efficacy. Additionally, baicalein attenuates the lipopolysaccharide-induced inflammatory response in vitro. Finally, baicalein can significantly improve doxycycline efficacy in mouse lung infection models. The present study showed that baicalein might be considered a lead compound, and it should be further optimized and developed as an adjuvant that helps combat antibiotic resistance. IMPORTANCE Doxycycline is an important broad-spectrum tetracycline antibiotic used for treating multiple human infections, but its resistance rates are recently rising globally. Thus, new agents capable of boosting the effectiveness of doxycycline need to be discovered. In this study, it was found that baicalein potentiates doxycycline against multidrug-resistant Gram-negative pathogens in vitro and in vivo. Due to its low cytotoxicity and resistance, the combination of baicalein and doxycycline provides a valuable clinical reference for selecting more effective therapeutic strategies for treating infections caused by multidrug-resistant Gram-negative clinical isolates.

Engineering Telodendrimer Nanocarriers for Monomeric Amphotericin B Delivery

Systemic fungal infections are an increasingly prevalent health problem. Amphotericin B (AmB), a hydrophobic polyene antibiotic, remains the drug of choice for life-threatening invasive fungal infections. However, it has dose-limiting side effects, including nephrotoxicity. The efficacy and toxicity of AmB are directly related to its aggregation state. Here, we report the preparation of a series of telodendrimer (TD) nanocarriers with the freely engineered core structures for AmB encapsulation to fine-tune AmB aggregation status. The reduced aggregation status correlates well with the optimized antifungal activity, attenuated hemolytic properties, and reduced cytotoxicity to mammalian cells. The optimized TD nanocarrier for monomeric AmB encapsulation significantly increases the therapeutic index, reduces the in vivo toxicity, and enhances antifungal effects in mouse models with Candida albicans infection in comparison to two common clinical formulations, i.e., Fungizone and AmBisome.

Bioinspired microrobots: Opportunities and challenges in targeted cancer therapy

Chemotherapy is still the most effective technique to treat many forms of cancer. However, it also carries a high risk of side effects. Numerous nanomedicines have been developed to avoid unintended consequences and significant negative effects of conventional therapies. Achieving targeted drug delivery also has several challenges. In this context, the development of microrobots is receiving considerable attention of formulation scientists and clinicians to overcome such challenges. Due to their mobility, microrobots can infiltrate tissues and reach tumor sites more quickly. Different types of microrobots, like custom-made moving bacteria, microengines powered by small bubbles, and hybrid spermbots, can be designed with complex features that are best for precise targeting of a wide range of cancers. In this review, we mainly focus on the idea of how microrobots can quickly target cancer cells and discuss specific advantages of microrobots. A brief summary of the microrobots' drug loading and release behavior is provided in this manuscript. This manuscript will assist clinicians and other medical professionals in diagnosing and treating cancer without surgery.

Rational Design of Hydrogels for Cationic Antimicrobial Peptide Delivery: A Molecular Modeling Approach

In light of the growing bacterial resistance to antibiotics and in the absence of the development of new antimicrobial agents, numerous antimicrobial delivery systems over the past decades have been developed with the aim to provide new alternatives to the antimicrobial treatment of infections. However, there are few studies that focus on the development of a rational design that is accurate based on a set of theoretical-computational methods that permit the prediction and the understanding of hydrogels regarding their interaction with cationic antimicrobial peptides (cAMPs) as potential sustained and localized delivery nanoplatforms of cAMP. To this aim, we employed docking and Molecular Dynamics simulations (MDs) that allowed us to propose a rational selection of hydrogel candidates based on the propensity to form intermolecular interactions with two types of cAMPs (MP-L and NCP-3a). For the design of the hydrogels, specific building blocks were considered, named monomers (MN), co-monomers (CM), and cross-linkers (CL). These building blocks were ranked by considering the interaction with two peptides (MP-L and NCP-3a) as receptors. The better proposed hydrogel candidates were composed of MN3-CM7-CL1 and MN4-CM5-CL1 termed HG1 and HG2, respectively. The results obtained by MDs show that the biggest differences between the hydrogels are in the CM, where HG2 has two carboxylic acids that allow the forming of greater amounts of hydrogen bonds (HBs) and salt bridges (SBs) with both cAMPs. Therefore, using theoretical-computational methods allowed for the obtaining of the best virtual hydrogel candidates according to affinity with the specific cAMP. In conclusion, this study showed that HG2 is the better candidate for future in vitro or in vivo experiments due to its possible capacity as a depot system and its potential sustained and localized delivery system of cAMP.

Effect of Lipophilic Chains on the Antitumor Effect of a Dendritic Nano Drug Delivery System

Oligoethylene glycol dendron (G2) has been used in drug delivery due to its unique dendritic structure and excellent properties. In order to investigate the effects of lipophilic chains on drug delivery, the amphiphilic hybrid compound G2-C18 is synthesized, and celastrol (CSL) is selected to prepare "core-shell" structured CSL-G2-C18 nanoparticles (NPs) via the antisolvent precipitation method. Meanwhile, CSL-G2 NPs are prepared as the control. The two NPs show similar particle sizes and polydispersity indexes, while their morphologies exhibit dramatic differences. CSL-G2 NPs are solid spherical particles, while G2-C18 NPs are vesicles. The two NPs present ideal stability and similar release tendencies. The in vitro toxicity results show that the cell inhibition effect of CSL-loaded NPs is significantly enhanced when compared with free CSL, and the antitumor effect of CSL-G2-C18 NPs is stronger than that of CSL-G2 NPs. The IC₅₀ value of CSL-G2 NPs and CSL-G2-C18 NPs is enhanced about 2.8-fold and 5-fold when compared with free CSL, respectively. The above results show that lipophilic chain-linking dendritic hybrid nanocarriers promote antitumor activity by affecting the morphology of NPs, which may aid in the selection of carrier designs.

Niosomes: a novel targeted drug delivery system for cancer

Recently, nanotechnology is involved in various fields of science, of which medicine is one of the most obvious. The use of nanoparticles in the process of treating and diagnosing diseases has created a novel way of therapeutic strategies with effective mechanisms of action. Also, due to the remarkable progress of personalized medicine, the effort is to reduce the side effects of treatment paths as much as possible and to provide targeted treatments. Therefore, the targeted delivery of drugs is important in different diseases, especially in patients who receive combined drugs, because the delivery of different drug structures requires different systems so that there is no change in the drug and its effectiveness. Niosomes are polymeric nanoparticles that show favorable characteristics in drug delivery. In addition to biocompatibility and high absorption, these nanoparticles also provide the possibility of reducing the drug dosage and targeting the release of drugs, as well as the delivery of both hydrophilic and lipophilic drugs by Niosome vesicles. Since various factors such as components, preparation, and optimization methods are effective in the size and formation of niosomal structures, in this review, the characteristics related to niosome vesicles were first examined and then the in silico tools for designing, prediction, and optimization were explained. Finally, anticancer drugs delivered by niosomes were compared and discussed to be a suitable model for designing therapeutic strategies. In this research, it has been tried to examine all the aspects required for drug delivery engineering using niosomes and finally, by presenting clinical examples of the use of these nanocarriers in cancer, its clinical characteristics were also expressed.

Combinatorial approaches of nanotherapeutics for inflammatory pathway targeted therapy of prostate cancer

Prostate cancer (PC) is the most prevalent male urogenital cancer worldwide. PC patients presenting an advanced or metastatic cancer succumb to the disease, even after therapeutic interventions including radiotherapy, surgery, androgen deprivation therapy (ADT), and chemotherapy. One of the hallmarks of PC is evading immune surveillance and chronic inflammation, which is a major challenge towards designing effective therapeutic formulations against PC. Chronic inflammation in PC is often characterized by tumor microenvironment alterations, epithelial-mesenchymal transition and extracellular matrix modifications. The inflammatory events are modulated by reactive nitrogen and oxygen species, inflammatory cytokines and chemokines. Major signaling pathways in PC includes androgen receptor, PI3K and NF-κB pathways and targeting these inter-linked pathways poses a major therapeutic challenge. Notably, many conventional treatments are clinically unsuccessful, due to lack of targetability and poor bioavailability of the therapeutics, untoward toxicity and multidrug resistance. The past decade witnessed an advancement of nanotechnology as an excellent therapeutic paradigm for PC therapy. Modern nanovectorization strategies such as stimuli-responsive and active PC targeting carriers offer controlled release patterns and superior anti-cancer effects. The current review initially describes the classification, inflammatory triggers and major inflammatory pathways of PC, various PC treatment strategies and their limitations. Subsequently, recent advancement in combinatorial nanotherapeutic approaches, which target PC inflammatory pathways, and the mechanism of action are discussed. Besides, the current clinical status and prospects of PC homing nanovectorization, and major challenges to be addressed towards the advancement PC therapy are also addressed.

Smart pH-responsive polyhydralazine/bortezomib nanoparticles for remodeling tumor microenvironment and enhancing chemotherapy

The clinical translation of nanomedicines has been impeded by the unfavorable tumor microenvironment (TME), particularly the tortuous vasculature networks, which significantly influence the transport and distribution of nanomedicines into tumors. In this work, a smart pH-responsive bortezomib (BTZ)-loaded polyhydralazine nanoparticle (PHDZ/BTZ) is presented, which has a great capacity to augment the accumulation of BTZ in tumors by dilating tumor blood vessels via specific release of vasodilator hydralazine (HDZ). The Lewis acid-base coordination effect between the boronic bond of BTZ and amino of HDZ empowered PHDZ/BTZ nanoparticles with great stability and high drug loading contents. Once triggered by the acidic tumor environment, HDZ could be released quickly to remodel TME through tumor vessel dilation, hypoxia attenuation, and lead to an increased intratumoral BTZ accumulation. Additionally, our investigation revealed that this pH-responsive nanoparticle dramatically suppressed tumor growth, inhibited the occurrence of lung metastasis with fewer side effects and induced immunogenic cell death (ICD), thereby eliciting immune activation including massive cytotoxic T lymphocytes (CTLs) infiltration in tumors and efficient serum proinflammatory cytokine secretion compared with free BTZ treatment. Thus, with efficient drug loading capacity and potent immune activation, PHDZ nanoparticles exhibit great potential in the delivery of boronic acid-containing drugs aimed at a wide range of diseases.

Pulmonary delivery of size-transformable nanoparticles improves tumor accumulation and penetration for chemo-sonodynamic combination therapy

Very little is currently known about how inhaled nanomedicine for lung cancer treatment overcomes biological barriers hampering the tumor availability of drug and nanoparticles. Here, we developed a size-transformable nanocarrier (~ 119 nm) in which small-size nanoparticles (~ 28 nm) were loaded in the large nanocarrier after the addition of modified hyaluronan and could be released upon size-transformation at tumor tissue. Subsequently, the pulmonary and tumor pharmacokinetics of the two nanocarriers containing 7-ethyl-10-hydroxycamptothecin (SN38) and a covalently linked fluorescent sonosensitizer were comparatively investigated after intratracheal instillation to mice bearing orthotopic Lewis lung carcinoma tumors. The results showed that both instilled nanoparticles seemed to transport drug to tumor by direct access and transcytosis of nanoparticles, and diffusion of the released drug with the latter accounting for a great proportion of the drug tumor bioavailability. Relative to the small-size nanocarrier, the size-transformable counterpart appeared to restrict the mucociliary and absorption clearances from the lung and the clearance from the tumor interstitium to circulation, leading to increases in lung and tumor bioavailability of SN38 by 58.5% and 199%, respectively. In addition, the size-transformable nanoformulation conferred deep tumor penetration and sustained levels of both sonosensitizer and SN38 within tumors and simultaneously exerted sonodynamic- and chemo-therapies. Overall, the pulmonary delivery of size-transformable nanocarrier could co-deliver sonosensitizer and drug to deep tumor sites with enhanced tumor accumulation to realize combination therapy in lung cancer.

From Prevention to Therapy: A Roadmap of Nanotechnologies to Stay Ahead of Future Pandemics

Several recent viral outbreaks, culminating in the COVID-19 pandemic, have illustrated the need for comprehensive improvement in the detection, control, and treatment of emerging viruses that exhibit the potential to cause epidemics. Nanotechnology approaches have the potential to make major contributions in all these areas. This perspective is intended to outline how nanotechnology can be employed to improve upon respiratory disease detection and containment measures, and therapeutics, with a particular emphasis on applications that can address key areas, including home diagnostics, contact tracing, and the evaluation of durability of vaccine protection over time and against future variants. Nanotechnology offers potent tools to address these needs, but further research is required to validate these applications to address needs of future epidemics.

Nano-chemically Modified Tetracycline-3 (nCMT-3) Attenuates Acute Lung Injury via Blocking sTREM-1 Release and NLRP3 Inflammasome Activation

BACKGROUND

Intratracheal (IT) lipopolysaccharide (LPS) causes severe acute lung injury (ALI) and systemic inflammation. CMT-3 has pleiotropic anti-inflammatory effects including matrix metalloproteinase (MMP) inhibition, attenuation of neutrophil (PMN) activation, and elastase release. CMT-3's poor water solubility limits its bioavailability when administered orally for treating ALI. We developed a nano-formulation of CMT-3 (nCMT-3) to test the hypothesis that the pleiotropic anti-inflammatory activities of IT nCMT-3 can attenuate LPS-induced ALI.

METHODS

C57BL/6 mice were treated with aerosolized IT nCMT-3 or saline, then had IT LPS or saline administered 2 h later. Tissues were harvested at 24 h. The effects of LPS and nCMT-3 on ALI were assessed by lung histology, MMP level/activity (zymography), NLRP3 protein, and activated caspase-1 levels. Blood and bronchoalveolar lavage fluid (BALF) cell counts, PMN elastase, and soluble triggering receptor expressed on myelocytes-1 (sTREM-1) levels, TNF-α, IL-1β, IL-6, IL-18, and BALF protein levels were also measured.

RESULTS

LPS-induced ALI was characterized by histologic lung injury (PMN infiltration, alveolar thickening, edema, and consolidation) elevated proMMP-2, -9 levels and activity, increased NLRP-3 protein and activated caspase-1 levels in lung tissue. LPS-induced increases in plasma and BALF levels of sTREM-1, TNF-α, IL-1β, IL-6, IL-18, PMN elastase and BALF protein levels demonstrate significant lung/systemic inflammation and capillary leak. nCMT-3 significantly ameliorated all of these LPS-induced inflammatory markers to control levels, and decreased the incidence of ALI.

CONCLUSIONS

Pre-treatment with nCMT3 significantly attenuates LPS-induced lung injury/inflammation by multiple mechanisms including: MMP activation, PMN elastase, sTREM-1 release, and NLRP3 inflammasome/caspase-1 activation.

Structure-Based Varieties of Polymeric Nanocarriers and Influences of Their Physicochemical Properties on Drug Delivery Profiles

Carriers are equally important as drugs. They can substantially improve bioavailability of cargos and safeguard healthy cells from toxic effects of certain therapeutics. Recently, polymeric nanocarriers (PNCs) have achieved significant success in delivering drugs not only to cells but also to subcellular organelles. Variety of natural sources, availability of different synthetic routes, versatile molecular architectures, exploitable physicochemical properties, biocompatibility, and biodegradability have presented polymers as one of the most desired materials for nanocarrier design. Recent innovative concepts and advances in PNC-associated nanotechnology are providing unprecedented opportunities to engineer nanocarriers and their functions. The efficiency of therapeutic loading has got considerably increased. Structural design-based varieties of PNCs are widely employed for the delivery of small therapeutic molecules to genes, and proteins. PNCs have gained ever-increasing attention and certainly paves the way to develop advanced nanomedicines. This article presents a comprehensive investigation of structural design-based varieties of PNCs and the influences of their physicochemical properties on drug delivery profiles with perspectives highlighting the inevitability of incorporating both the multi-stimuli-responsive and multi-drug delivery properties in a single carrier to design intelligent PNCs as new and emerging research directions in this rapidly developing area.

Actively Targeted Nanomedicines in Breast Cancer: From Pre-Clinal Investigation to Clinic

Simple Summary

Despite all the efforts and advances made in the treatment of breast cancer, this pathology continues to be one of the main causes of cancer death in women, particularly triple-negative breast cancer (TNBC), and, although to a lesser degree, HER-2 receptor-positive tumors. Chemotherapy is one of the main treatments available. However, it shows numerous limitations due to its lack of selectivity. In this sense, the selective delivery of antineoplastics to cancer cells can reduce their adverse effects and increase their efficacy. The use of active targeted nanomedicine is a good strategy to achieve this selective chemotherapy. In fact, in recent decades, several active targeted nanoformulations have been approved or reached clinical investigation with excellent results. Among all nanomedicines, antibody-drug conjugates are the most promising.

Abstract

Breast cancer is one of the most frequently diagnosed tumors and the second leading cause of cancer death in women worldwide. The use of nanosystems specifically targeted to tumor cells (active targeting) can be an excellent therapeutic tool to improve and optimize current chemotherapy for this type of neoplasm, since they make it possible to reduce the toxicity and, in some cases, increase the efficacy of antineoplastic drugs. Currently, there are 14 nanomedicines that have reached the clinic for the treatment of breast cancer, 4 of which are already approved (Kadcyla^®, Enhertu^®, Trodelvy^®, and Abraxane^®). Most of these nanomedicines are antibody–drug conjugates. In the case of HER-2-positive breast cancer, these conjugates (Kadcyla^®, Enhertu^®, Trastuzumab-duocarmycin, RC48, and HT19-MMAF) target HER-2 receptors, and incorporate maytansinoid, deruxtecan, duocarmicyn, or auristatins as antineoplastics. In TNBC these conjugates (Trodelvy^®, Glembatumumab-Vedotin, Ladiratuzumab-vedotin, Cofetuzumab-pelidotin, and PF-06647263) are directed against various targets, in particular Trop-2 glycoprotein, NMB glycoprotein, Zinc transporter LIV-1, and Ephrin receptor-4, to achieve this selective accumulation, and include campthotecins, calicheamins, or auristatins as drugs. Apart from the antibody–drug conjugates, there are other active targeted nanosystems that have reached the clinic for the treatment of these tumors such as Abraxane^® and Nab-rapamicyn (albumin nanoparticles entrapping placlitaxel and rapamycin respectively) and various liposomes (MM-302, C225-ILS-Dox, and MM-310) loaded with doxorubicin or docetaxel and coated with ligands targeted to Ephrin A2, EPGF, or HER-2 receptors. In this work, all these active targeted nanomedicines are discussed, analyzing their advantages and disadvantages over conventional chemotherapy as well as the challenges involved in their lab to clinical translation. In addition, examples of formulations developed and evaluated at the preclinical level are also discussed.

Structurally defined tandem-responsive nanoassemblies composed of dipeptide-based photosensitive derivatives and hypoxia-activated camptothecin prodrugs against primary and metastatic breast tumors

Substantial progress in the use of chemo-photodynamic nano-drug delivery systems (nano-DDS) for the treatment of the malignant breast cancer has been achieved. The inability to customize precise nanostructures, however, has limited the therapeutic efficacy of the prepared nano-DDS to date. Here, we report a structurally defined tandem-responsive chemo-photosensitive co-nanoassembly to eliminate primary breast tumor and prevent lung metastasis. This both-in-one co-nanoassembly is prepared by assembling a biocompatible photosensitive derivative (pheophorbide-diphenylalanine peptide, PPA-DA) with a hypoxia-activated camptothecin (CPT) prodrug [(4-nitrophenyl) formate camptothecin, N-CPT]. According to computational simulations, the co-assembly nanostructure is not the classical core-shell type, but consists of many small microphase regions. Upon exposure to a 660 nm laser, PPA-DA induce high levels of ROS production to effectively achieve the apoptosis of normoxic cancer cells. Subsequently, the hypoxia-activated N-CPT and CPT spatially penetrate deep into the hypoxic region of the tumor and suppress hypoxia-induced tumor metastasis. Benefiting from the rational design of the chemo-photodynamic both-in-one nano-DDS, these nanomedicines exhibit a promising potential in the inhibition of difficult-to-treat breast tumor metastasis in patients with breast cancer.

Stimuli-Sensitive Linear-Dendritic Block Copolymer-Drug Prodrug as a Nanoplatform for Tumor Combination Therapy

Linear-dendritic block copolymer (LDBCs) are highly attractive candidates for smart drug-delivery vehicles. Herein, an amphiphilic poly[(ethylene glycol) methyl ether methacrylate] (POEGMA) linear-peptide dendritic prodrug of doxorubicin (DOX) prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization is reported. The hydrophobic-dye-based photosensitizer chlorin e6 (Ce6) is employed for encapsulation in the prodrug nanoparticles (NPs) to obtain an LDBCs-based drug-delivery system (LD-DOX/Ce6) that offers a combination cancer therapy. Due to the presence of Gly-Phe-Leu-Gly peptides and hydrazone bonds in the prodrug structure, LD-DOX/Ce6 is degraded into small fragments, thus specifically triggering the intracellular release of DOX and Ce6 in the tumor microenvironment. Bioinformatics analysis suggests that LD-DOX/Ce6 with laser irradiation treatment significantly induces apoptosis, DNA damage, and cell cycle arrest. The combination treatment can not only suppress tumor growth, but also significantly reduce tumor metastasis compared with treatments with DOX or Ce6 through regulating EMT pathway, TGFβ pathway, angiogenesis, and the hypoxia pathway. LD-DOX/Ce6 displays a synergistic chemo-photodynamic antitumor efficacy, resulting in a high inhibition in tumor growth and metastasis, while maintaining an excellent biosafety. Therefore, this study demonstrates the potential of the biodegradable and tumor-microenvironment-responsive LDBCs as an intelligent multifunctional drug-delivery vehicle for high-efficiency cancer combination therapy.

GSH-responsive poly-resveratrol based nanoparticles for effective drug delivery and reversing multidrug resistance

Cancer poses a serious threat to human health and is the most common cause of human death. Polymer-based nanomedicines are presently used to enhance the treatment effectiveness and decrease the systemic toxicity of chemotherapeutic agents. However, the disadvantage of currently polymeric carriers is without therapy procedure. Herein, for the first time, glutathione (GSH)-responsive polymer (PRES) with anti-cancer effect was synthesized following the condensation–polymerization method using resveratrol (RES) and 3,3′-dithiodipropionic acid. PRES can not only suppress the tumor cells growth but can also self-assemble into nanoparticles (∼93 nm) for delivering antitumor drugs, such as paclitaxel (PTX@PRES NPs). The system could achieve high drug loading (∼7%) and overcome multidrug resistance (MDR). The results from the in vitro studies revealed that the NPs formed of PRES were stable in the systemic circulation, while could be efficiently degraded in tumor cells high GSH environment. Results from cytotoxicity tests confirmed that PTX@PRES NPs could effectively suppress the growth of cancer cells (A549) and drug-resistant cells (A549/PTX). The NPs could also be used to significantly increase the therapeutic efficacy of the drugs in A549/PTX tumor-bearing mice. In vivo investigations also demonstrated that the PRES-based NPs exhibited tumor inhibition effects. In summary, we report that the GSH-responsive polymer synthesized by us exhibited multiple interesting functions and could be used for effective drug delivery. The polymer exhibited good therapeutic effects and could be used to overcome MDR. Thus, the synthesized system can be used to develop a new strategy for treating cancer.

Emerging nanoformulation strategies for phytocompounds and applications from drug delivery to phototherapy to imaging

Over thousands of years, natural bioactive compounds derived from plants (bioactive phytocompounds, BPCs) have been used worldwide to address human health issues. Today, they are a significant resource for drug discovery in the development of modern medicines. Although many BPCs have promising biological activities, most of them cannot be effectively utilized in drugs for therapeutic applications because of their inherent limitations of low solubility, structural instability, short half-life, poor bioavailability, and non-specific distribution to organs. Researchers have utilized emerging nanoformulation (NF) technologies to overcome these limitations as they have demonstrated great potential to improve the solubility, stability, and pharmacokinetic and pharmacodynamic characteristics of BPCs. This review exemplifies NF strategies for resolving the issues associated with BPCs and summarizes recent advances in their preclinical and clinical applications for imaging and therapy. This review also highlights how innovative NF technologies play a leading role in next-generation BPC-based drug development for extended therapeutic applications. Finally, this review discusses the opportunities to take BPCs with meaningful clinical impact from bench to bedside and extend the patent life of BPC-based medicines with new formulations or application to new adjacent diseases beyond the primary drug indications.

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Natural bioactive phytocompounds derived from plants have been used worldwide to address human health issues. However, most of them cannot be effectively utilized in drugs for therapeutic applications because of their inherent limitations.

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Nanoformulation approach has recently been underlined as an emerging pharmaceutical strategy to overcome the intrinsic drawbacks of bioactive phytocompounds.

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Various types of nanoformulation and their up-to-date applications for targeted delivery, phototherapy, and imaging are reviewed. Finally, their clinical implications for the repurposing of bioactive phytocompounds are deliberated.

Advances in Non-Animal Testing Approaches towards Accelerated Clinical Translation of Novel Nanotheranostic Therapeutics for Central Nervous System Disorders

Nanotheranostics constitute a novel drug delivery system approach to improving systemic, brain-targeted delivery of diagnostic imaging agents and pharmacological moieties in one rational carrier platform. While there have been notable successes in this field, currently, the clinical translation of such delivery systems for the treatment of neurological disorders has been limited by the inadequacy of correlating in vitro and in vivo data on blood-brain barrier (BBB) permeation and biocompatibility of nanomaterials. This review aims to identify the most contemporary non-invasive approaches for BBB crossing using nanotheranostics as a novel drug delivery strategy and current non-animal-based models for assessing the safety and efficiency of such formulations. This review will also address current and future directions of select in vitro models for reducing the cumbersome and laborious mandate for testing exclusively in animals. It is hoped these non-animal-based modelling approaches will facilitate researchers in optimising promising multifunctional nanocarriers with a view to accelerating clinical testing and authorisation applications. By rational design and appropriate selection of characterised and validated models, ranging from monolayer cell cultures to organ-on-chip microfluidics, promising nanotheranostic particles with modular and rational design can be screened in high-throughput models with robust predictive power. Thus, this article serves to highlight abbreviated research and development possibilities with clinical translational relevance for developing novel nanomaterial-based neuropharmaceuticals for therapy in CNS disorders. By generating predictive data for prospective nanomedicines using validated in vitro models for supporting clinical applications in lieu of requiring extensive use of in vivo animal models that have notable limitations, it is hoped that there will be a burgeoning in the nanotherapy of CNS disorders by virtue of accelerated lead identification through screening, optimisation through rational design for brain-targeted delivery across the BBB and clinical testing and approval using fewer animals. Additionally, by using models with tissue of human origin, reproducible therapeutically relevant nanomedicine delivery and individualised therapy can be realised.

Triple negative breast cancer and non-small cell lung cancer: Clinical challenges and nano-formulation approaches

Triple negative breast cancer (TNBC) and non-small cell lung cancer (NSCLC) are amongst the most aggressive forms of solid tumors. TNBC is highlighted by absence of genetic components of progesterone receptor, HER2/neu and estrogen receptor in breast cancer. NSCLC is characterized by integration of malignant carcinoma into respiratory system. Both cancers are associated with poor median and overall survival rates with low progression free survival with high incidences of relapse. These cancers are characterized by tumor heterogeneity, genetic mutations, generation of cancer-stem cells, immune-resistance and chemoresistance. Further, these neoplasms have been reported for tumor cross-talk into second primary cancers for each other. Current chemotherapeutic regimens include usage of multiple agents in tandem to affect tumor cells through multiple mechanisms with various such combinations being clinically tested. However, lack of controlled delivery and effective temporospatial presence of chemotherapeutics has resulted in suboptimal therapeutic response. Consequently, passive targeted albumin bound paclitaxel and PEGylated liposomal doxorubicin have been clinically used and tested with newer drugs for improved therapeutic efficacy in these cancers. Active targeting of nanocarriers against surface overexpressed proteins in both neoplasms have been explored. However, use of single agent nanoparticulate formulations against both cancers have failed to elicit desired outcomes. This review aims to identify clinical unmet need in these cancers while establishing a correlation with tested nano-formulation approaches and issues with preclinical to clinical translation. Lipid and polymer-based drug-drug and drug-gene combinatorial nanocarriers delivering multiple chemotherapeutics simultaneously to desired site of action have been detailed. Finally, emerging opportunities such as pharmacological targets (immune check point and epigentic modulators) as well as gene-based modulation (siRNA/CRISPR/Cas9) and the nano-formulation challenges for effective treatment of both cancers have been explored.

Entrapment of Macrophage-Target Nanoparticles by Yeast Microparticles for Rhein Delivery in Ulcerative Colitis Treatment

In this study, we developed an advanced colitis-targeted nanoparticles (NPs)-into-yeast cell wall microparticles (YPs) drug delivery system for ulcerative colitis (UC) therapy. In brief, YPs entrap hyaluronic acid (HA), and polyethylenimine (PEI) modified rhein (RH)-loaded ovalbumin NPs (HA/PEI-RH NPs) to form HA/PEI-RH NYPs. YPs can make HA/PEI-RH NPs pass through gastric environment stably and be degraded by β-glucanase to promote drug release from HA/PEI-RH NYPs in the colon. Cellular uptake evaluation confirmed that HA/PEI-RH NPs could specifically target and enhance the uptake rate via HA ligands. In biodistribution studies, HA/PEI-RH NYPs were able to efficiently accumulate in the inflammed colon in mice. In vivo experiments revealed that the HA/PEI-RH NYPs could significantly alleviate inflammation by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Therefore, HA/PEI-RH NYPs have advantages of good gastric stability, β-glucanase-sensitive release ability, macrophage-targeted ability, and anti-UC effects. These advantages indicate YPs-entrapped multifunctional NPs are a promising oral drug delivery system for UC therapy.

Facial Solid-Phase Synthesis of Well-Defined Zwitterionic Amphiphiles for Enhanced Anticancer Drug Delivery

Serum protein adsorption on the nanoparticle surface determines the biological identity of polymeric nanocarriers and critically impacts the in vivo stability following intravenous injection. Ultrahydrophilic surfaces are desired in delivery systems to reduce the serum protein corona formation, prolong drug pharmacokinetics, and improve the in vivo performance of nanotherapeutics. Zwitterionic polymers have been explored as alternative stealth materials for biomedical applications. In this study, we employed facial solid-phase peptide chemistry (SPPC) to synthesize multifunctional zwitterionic amphiphiles for application as a drug delivery vehicle. SPPC facilitates synthesis and purification of the well-defined dendritic amphiphiles, yielding high-purity and precise architecture. Zwitterionic glycerylphosphorylcholine (GPC) was selected as a surface moiety for the construction of a ultrahydrophilic dendron, which was coupled on solid phase to a hydrophobic dendron using multiple rhein (Rh) molecules as drug-binding moieties (DBMs) for doxorubicin (DOX) loading via pi-pi stacking and hydrogen bonding. The resulting zwitterionic amphiphilic Janus dendrimer (denoted as GPC₈-Rh₄) showed improved stabilities and sustained drug release compared to the analogue with poly(ethylene glycol) (PEG) surface (PEG^5k-Rh₄). In vivo studies in xenograft mouse tumor models demonstrated that the DOX-GPC₈-Rh₄ nanoformulation significantly improved anticancer effects compared to DOX-PEG^5k-Rh₄, owing to the improved in vivo pharmacokinetics and increased tumor accumulation.

Targeted drug delivery strategies for precision medicines

Progress in the field of precision medicine has changed the landscape of cancer therapy. Precision medicine is propelled by technologies that enable molecular profiling, genomic analysis, and optimized drug design to tailor treatments for individual patients. Although precision medicines have resulted in some clinical successes, the use of many potential therapeutics has been hindered by pharmacological issues, including toxicities and drug resistance. Drug delivery materials and approaches have now advanced to a point where they can enable the modulation of a drug's pharmacological parameters without compromising the desired effect on molecular targets. Specifically, they can modulate a drug's pharmacokinetics, stability, absorption, and exposure to tumours and healthy tissues, and facilitate the administration of synergistic drug combinations. This Review highlights recent progress in precision therapeutics and drug delivery, and identifies opportunities for strategies to improve the therapeutic index of cancer drugs, and consequently, clinical outcomes.

The biomedical significance of multifunctional nanobiomaterials: The key components for site-specific delivery of therapeutics

The emergence of nanotechnology has provided the possibilities to overcome the potential problems associated with the development of pharmaceuticals including the low solubility, non-specific cellular uptake or action, and rapid clearance. Regarding the biomaterials (BMs), huge efforts have been made for improving their multi-functionalities via incorporation of various nanomaterials (NMs). Nanocomposite hydrogels with suitable properties could exhibit a variety of beneficial effects in biomedicine particularly in the delivery of therapeutics or tissue engineering. NMs including the silica- or carbon-based ones are capable of integration into various BMs that might be due to their special compositions or properties such as the hydrophilicity, hydrophobicity, magnetic or electrical characteristics, and responsiveness to various stimuli. This might provide multi-functional nanobiomaterials against a wide variety of disorders. Meanwhile, inappropriate distribution or penetration into the cells or tissues, bio-nano interface complexity, targeting ability loss, or any other unpredicted phenomena are the serious challenging issues. Computational simulations and models enable development of NMs with optimal characteristics and provide a deeper knowledge of NM interaction with biosystems. This review highlights the biomedical significance of the multifunctional NMs particularly those applied for the development of 2-D or 3-D BMs for a variety of applications including the site-specific delivery of therapeutics. The powerful impacts of the computational techniques on the design process of NMs, quantitation and prediction of protein corona formation, risk assessment, and individualized therapy for improved therapeutic outcomes have also been discussed.

The design and synthesis of redox-responsive oridonin polymeric prodrug micelle formulation for effective gastric cancer therapy

Advanced gastric cancer (GC) is a significant threat to human health. Oridonin (ORI), isolated from the Chinese herb Rabdosia rubescens, has demonstrated great potential in GC therapy. However, the application of ORI in the clinic was greatly hindered by its poor solubility, low bioavailability, and rapid plasma clearance. Herein, a simple and novel redox-sensitive ORI polymeric prodrug formulation was synthesized by covalently attaching ORI to poly(ethylene glycol)-block-poly(l-lysine) via a disulfide linker, which can self-assemble into micelles (P-ss-ORI) in aqueous solutions and produce low critical micelle concentrations (about 10 mg L^-1), characterized by small size (about 80 nm), negative surface charge (about -12 mV), and high drug loading efficiency (18.7%). The in vitro drug release study showed that P-ss-ORI can rapidly and completely release ORI in a glutathione (GSH)-rich environment and under low pH conditions. Moreover, in vitro and in vivo investigations confirmed that P-ss-ORI could remarkably extend the blood circulation time of ORI, enrich in tumor tissue, be effectively endocytosed by GC cancer cells, and quickly and completely release the drug under high intracellular GSH concentrations and low pH conditions, all these characteristics ultimately inhibit the growth of GC. This redox and pH dual-responsive P-ss-ORI formulation provides a useful strategy for GC treatment.

Nanotechnology and Nanocarrier-Based Drug Delivery as the Potential Therapeutic Strategy for Glioblastoma Multiforme: An Update

Simple Summary

Glioblastoma multiforme (GBM) are among the most lethal tumors. The highly invasive nature and presence of GBM stem cells, as well as the blood brain barrier (BBB) which limits chemotherapeutic drugs from entering the tumor mass, account for the high chance of treatment failure. Recent developments have found that nanoparticles can be conjugated to liposomes, dendrimers, metal irons, or polymeric micelles, which enhance the drug-loaded compounds to efficiently penetrate the BBB, thus offering new possibilities for overcoming GBM stem cell-mediated resistance to chemotherapy and radiation therapy. In addition, there have been new emerging strategies that use nanocarriers for successful GBM treatment in animal models. This review highlights the recent development of nanotechnology and nanocarrier-based drug delivery for treatment of GBMs, which may be a promising therapeutic strategy for this tumor entity.

Abstract

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor with poor prognosis. The heterogeneous and aggressive nature of GBMs increases the difficulty of current standard treatment. The presence of GBM stem cells and the blood brain barrier (BBB) further contribute to the most important compromise of chemotherapy and radiation therapy. Current suggestions to optimize GBM patients’ outcomes favor controlled targeted delivery of chemotherapeutic agents to GBM cells through the BBB using nanoparticles and monoclonal antibodies. Nanotechnology and nanocarrier-based drug delivery have recently gained attention due to the characteristics of biosafety, sustained drug release, increased solubility, and enhanced drug bioactivity and BBB penetrability. In this review, we focused on recently developed nanoparticles and emerging strategies using nanocarriers for the treatment of GBMs. Current studies using nanoparticles or nanocarrier-based drug delivery system for treatment of GBMs in clinical trials, as well as the advantages and limitations, were also reviewed.

Synthesis and characterization of biodegradable and antioxidant phosphazene-tannic acid nanospheres and their utilization as drug carrier material

In this study, hexachlorocyclotriphosphazene (HCCP) and tannic acid (TA) were used at different stoichiometric ratios to synthesize cyclomatrix-type polymeric materials with different surface features and dimensions. Using different reactive ratios, the structure and surface functional groups of the synthesized polymeric particles were explained using Fourier-Transform Infrared Spectroscopic (FTIR), Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray Photoelectron Spectroscopy (XPS) and Thermogravimetric (TG) analysis techniques. With morphologically fully spherical structure and mean 234.82 ± 49.37 nm dimensions, Phz-TA (4:1) nanospheres were researched for in vitro biodegradability, antioxidant features, and usability as a drug release system. In vitro biodegradability of Phz-TA (4:1) nanospheres was investigated at pH = 7.0 and pH = 1.2. Determined to degrade in 8-10 h at these pH values, nanospheres were used for releasing of Rhodamine 6G as a model drug. Due to the rich phenolic structure of the contained tannic acid units, nanospheres were determined to simultaneously have antioxidant features. Thus, this study determined that Phz-TA nanospheres with in vitro biodegradability and antioxidant features are promising polymeric materials for use as a potential drug-carrier in the future.

Engineering microrobots for targeted cancer therapies from a medical perspective

Systemic chemotherapy remains the backbone of many cancer treatments. Due to its untargeted nature and the severe side effects it can cause, numerous nanomedicine approaches have been developed to overcome these issues. However, targeted delivery of therapeutics remains challenging. Engineering microrobots is increasingly receiving attention in this regard. Their functionalities, particularly their motility, allow microrobots to penetrate tissues and reach cancers more efficiently. Here, we highlight how different microrobots, ranging from tailor-made motile bacteria and tiny bubble-propelled microengines to hybrid spermbots, can be engineered to integrate sophisticated features optimised for precision-targeting of a wide range of cancers. Towards this, we highlight the importance of integrating clinicians, the public and cancer patients early on in the development of these novel technologies.

Rational Design of DNA Framework-Based Hybrid Nanomaterials for Anticancer Drug Delivery

Engineered DNA frameworks have been extensively exploited as affinity scaffolds for drug delivery. However, few studies focus on the rational design to comprehensively improve their stability, internalization kinetics, and drug loading efficiency. Herein, DNA framework-based hybrid nanomaterials are rationally engineered by using a molecular docking tool, where the framework acts as a template to support conjugated polymers. The hybrid materials exhibit high stability in biofluids owning to the multiple interactions between DNA and cationic conjugated polymer. Through molecular docking, it is found that a specific structure of the conjugated polymer at major grooves of DNA gives rise to a unique pocket for small-molecular drug doxorubicin (DOX) yielding lower binding energy than conventional DOX binding sites. This increases the binding affinity of DOX, allowing for high drug loading content and efficiency, and preventing drug leakage under physiological condition. As a proof of concept, the hybrid nanomaterials equipped with aptamer are used to carry DOX and antisense oligonucleotide G3139, which effectively inhibits solid tumor growth and shows negligible side effects on mice. It is anticipated that this approach would find broad applications in hybrid materials design and precise medicine.

Characterization and Evaluation of Bone-Derived Nanoparticles as a Novel pH-Responsive Carrier for Delivery of Doxorubicin into Breast Cancer Cells

Background: The limitations of conventional treatment modalities in cancer, especially in breast cancer, facilitated the necessity for developing a safer drug delivery system (DDS). Inorganic nano-carriers based on calcium phosphates such as hydroxyapatite (HA) and carbonate apatite (CA) have gained attention due to their biocompatibility, reduced toxicity, and improved therapeutic efficacy. Methods: In this study, the potential of goose bone ash (GBA), a natural derivative of HA or CA, was exploited as a pH-responsive carrier to successfully deliver doxorubicin (DOX), an anthracycline drug into breast cancer cells (e.g., MCF-7 and MDA-MB-231 cells). GBA in either pristine form or in suspension was characterized in terms of size, morphology, functional groups, cellular internalization, cytotoxicity, pH-responsive drug (DOX) release, and protein corona analysis. Results: The pH-responsive drug release study demonstrated the prompt release of DOX from GBA through its disintegration in acidic pH (5.5–6.5), which mimics the pH of the endosomal and lysosomal compartments as well as the stability of GBA in physiological pH (pH 7.5). The result of DOX binding with GBA indicated an increment in binding affinity with increasing concentrations of DOX. Cell viability and cytotoxicity analysis showed no innate toxicity of GBA particles. Both qualitative and quantitative cellular uptake analysis in both cell lines displayed an enhanced cellular internalization of DOX-loaded GBA compared to free DOX molecules. The protein corona spontaneously formed on the surface of GBA particles exhibited its affinity toward transport proteins, structural proteins, and a few other selective proteins. The adsorption of transport proteins could extend the circulation half-life in biological environment and increase the accumulation of the drug-loaded NPs through the enhanced permeability and retention (EPR) effect at the tumor site. Conclusion: These findings highlight the potential of GBA as a DDS to successfully deliver therapeutics into breast cancer cells.

Telodendrimers: Promising Architectural Polymers for Drug Delivery

Architectural complexity has played a key role in enhancing the efficacy of nanocarriers for a variety of applications, including those in the biomedical field. With the continued evolution in designing macromolecules-based nanoparticles for drug delivery, the combination approach of using important features of linear polymers with dendrimers has offered an advantageous and viable platform. Such nanostructures, which are commonly referred to as telodendrimers, are hybrids of linear polymers covalently linked with different dendrimer generations and backbones. There is considerable variety in selection from widely studied linear polymers and dendrimers, which can help tune the overall composition of the resulting hybrid structures. This review highlights the advances in articulating syntheses of these macromolecules, and the contributions these are making in facilitating therapeutic administration. Limited progress has been made in the design and synthesis of these hybrid macromolecules, and it is through an understanding of their physicochemical properties and aqueous self-assembly that one can expect to fully exploit their potential in drug delivery.

Tailoring Azlactone-Based Block Copolymers for Stimuli-Responsive Disassembly of Nanocarriers

Stimuli-responsive nanoparticles based on a reactive block copolymers (BCPs) of poly(ethylene glycol)-b-poly(2-vinyl-4,4-dimethylazlactone) (PEG-b-PVDMA) have been fabricated for loading and controlled release of molecular cargoes. Microphase segregation of PEG-b-PVDMA BCPs enables the construction of well-defined nanoparticles in aqueous solutions. The azlactone groups in VDMA repeat units offer active sites for hydrophilization of the BCPs and functionalization by primary amines. The hydrophilization of PEG-b-PVDMA BCPs induces gradual reconstruction and dissociation of the BCP nanoparticles. Functional primary amines can be conjugated to PEG-b-PVDMA BCPs, yielding azobenzene- and pyridine-containing BCPs. The self-assembled nanoparticles made from the functionalized BCPs can disassemble in response to different external stimuli (e.g., addition of β-cyclodextrin and pH changes). The gradual reconstruction of functionalized PEG-b-PVDMA BCP nanoparticles caused by hydrolysis of residual azlactone groups provides a novel method to engineer sub-50 nm, well-dispersed, stimuli-responsive nanoparticles. These nanoparticles can incorporate molecular cargoes and release them upon external stimuli, making the azlactone-containing BCPs attractive platforms for the development of controlled delivery vehicles.

Synergistic inhibition of metastatic breast cancer by dual-chemotherapy with excipient-free rhein/DOX nanodispersions

BACKGROUND

The management of metastatic cancer remains a major challenge in cancer therapy worldwide. The targeted delivery of chemotherapeutic drugs through rationally designed formulations is one potential therapeutic option. Notably, excipient-free nanodispersions that are entirely composed of pharmaceutically active molecules have been evaluated as promising candidates for the next generation of drug formulations. Formulated from the self-assembly of drug molecules, these nanodispersions enable the safe and effective delivery of therapeutic drugs to local disease lesions. Here, we developed a novel and green approach for preparing nanoparticles via the self-assembly of rhein (RHE) and doxorubicin (DOX) molecules, named RHE/DOX nanoparticles (RD NPs); this assembly was associated with the interaction force and did not involve any organic solvents.

RESULTS

According to molecular dynamics (MD) simulations, DOX molecules tend to assemble around RHE molecules through intermolecular forces. This intermolecular retention of DOX was further improved by the nanosizing effect of RD NPs. Compared to free DOX, RD NPs exerted a slightly stronger inhibitory effect on 4T1 cells in the scratch healing assay. As a dual drug-loaded nanoformulation, the efficacy of RD NPs against tumor cells in vitro was synergistically enhanced. Compared to free DOX, the combination of DOX and RHE in nanoparticles exerted a synergistic effect with a combination index (CI) value of 0.51 and showed a stronger ability to induce cell apoptosis. Furthermore, the RD NP treatment not only effectively suppressed primary tumor growth but also significantly inhibited tumor metastasis both in vitro and in vivo, with a better safety profile.

CONCLUSIONS

The generation of pure nanodrugs via a self-assembly approach might hold promise for the development of more efficient and novel excipient-free nanodispersions, particularly for two small molecular antitumor drugs that potentially exert synergistic antiproliferative effects on metastatic breast cancer.

A combined "eat me/don't eat me" strategy based on extracellular vesicles for anticancer nanomedicine

A long-term and huge challenge in nanomedicine is the substantial uptake and rapid clearance mediated by the mononuclear phagocyte system (MPS), which enormously hinders the development of nanodrugs. Inspired by the natural merits of extracellular vesicles, we therefore developed a combined "eat me/don't eat me" strategy in an effort to achieve MPS escape and efficient drug delivery. Methodologically, cationized mannan-modified extracellular vesicles derived from DC2.4 cells were administered to saturate the MPS (eat me strategy). Then, nanocarriers fused to CD47-enriched exosomes originated from human serum were administered to evade phagocytosis by MPS (don't eat me strategy). The nanocarriers were also loaded with antitumor drugs and functionalized with a novel homing peptide to promote the tumour tissue accumulation and cancer cell uptake (eat me strategy). The concept was proven in vitro as evidenced by the reduced endocytosis of macrophages and enhanced uptake by tumour cells, whereas prolonged circulation time and increased tumour accumulation were demonstrated in vivo. Specially, the strategy induced a 123.53% increase in tumour distribution compared to conventional nanocarrier. The study both shed light on the challenge overcoming of phagocytic evasion and provided a strategy for significantly improving therapeutic outcomes, potentially permitting active drug delivery via targeted nanomedicines.