pH-responsive high stability polymeric nanoparticles for targeted delivery of anticancer therapeutics

Current multi-scale biomaterials for tissue regeneration following spinal cord injury

Spinal cord injury (SCI) may cause loss of motor and sensory function, autonomic dysfunction, and thus disrupt the quality of life of patients, leading to severe disability and significant psychological, social, and economic burden. At present, existing therapy for SCI have limited ability to promote neural function recovery, and there is an urgent need to develop innovative regenerative approaches to repair SCI. Biomaterials have become a promising strategy to promote the regeneration and repair of damaged nerve tissue after SCI. Biomaterials can provide support for nerve tissue by filling cavities, and improve local inflammatory responses and reshape extracellular matrix structures through unique biochemical properties to create the optimal microenvironment at the SCI site, thereby promoting neurogenesis and reconnecting damaged spinal cord tissue. Considering the importance of biomaterials in repairing SCI, this article reviews the latest progress of multi-scale biomaterials in SCI treatment and tissue regeneration, and evaluates the relevant technologies for manufacturing biomaterials.

Fillable Magnetic Microrobots for Drug Delivery to Cardiac Tissues In Vitro

Many cardiac diseases, such as arrhythmia or cardiogenic shock, cause irregular beating patterns that must be regulated to prevent disease progression toward heart failure. Treatments can include invasive surgery or high systemic drug dosages, which lack precision, localization, and control. Drug delivery systems (DDSs) that can deliver cargo to the cardiac injury site could address these unmet clinical challenges. Here, a microrobotic DDS that can be mobilized to specific sites via magnetic control is presented. This DDS incorporates an internal chamber that can protect drug cargo. Furthermore, the DDS contains a tunable thermosensitive sealing layer that gradually degrades upon exposure to body temperature, enabling prolonged drug release. Once loaded with the small molecule drug norepinephrine, this microrobotic DDS modulated beating frequency in induced pluripotent stem-cell derived cardiomyocytes (iPSC-CMs) in a dose-dependent manner, thus simulating drug delivery to cardiac cells in vitro. The DDS also navigates several maze-like structures seeded with cardiomyocytes to demonstrate precise locomotion under a rotating low-intensity magnetic field and on-site drug delivery. This work demonstrates the utility of a magnetically actuating DDS for precise, localized, and controlled drug delivery which is of interest for a myriad of future opportunities such as in treating cardiac diseases.

A pH-Responsive Protein Assembly through Clustering of a Charge-Tunable Single Amino Acid Repeat

Specific targeting of tumor cells is a key to achieving high therapeutic efficacy while minimizing off-target side effects. As a general approach to targeting diverse tumor cells, considerable attention has been paid to the tumor microenvironment, particularly its slightly acidic pH (6.5-6.8). However, existing pH-sensitive nanomaterials, based on organic polymers and proteins, often lack sufficient pH sensitivity and specificity. Here, we demonstrate a strategy to construct a pH-responsive protein assembly through clustering of a single amino acid repeat as a charge-tunable moiety. As a proof of concept, a histidine peptide with varying lengths was displayed on the surface of a ferritin assembly composed of 24 subunits by genetic fusion to a subunit. The resulting self-assembled ferritin particles, termed "pHerricle (pH-responsive ferritin particle)", were shown to exhibit a specific binding to tumor cells in response to pH changes through cooperative effects of histidine peptides. Increasing the histidine peptide length from 0 to 12 residues increased the pHerricle's cell-binding capacity by 21-fold and allowed modulation of the targetable pH range. General applicability as a tumor cell-targeting platform was shown by specific delivery of a cytotoxic cargo by the pHerricle into tumor cells of various origins in a pH-dependent manner.

Selenium Nanoparticles Synergize with a KRAS Nanovaccine against Breast Cancer

Selenium (Se) is an element crucial for human health, known for its anticancer properties. Although selenium nanoparticles (SeNPs) have shown lower toxicity and higher biocompatibility than other Se compounds, bare SeNPs are unstable in aqueous solutions. In this study, several materials, including bovine serum albumin (BSA), chitosan, polymethyl vinyl ether-alt-maleic anhydride, and tocopherol polyethylene glycol succinate, are explored to develop stable SeNPs and further evaluate their potential as candidates for cancer treatment. All optimized SeNP are spherical, <100 nm, and with a narrow size distribution. BSA-stabilized SeNPs produced under acidic conditions present the highest stability in medium, plasma, and at physiological pH, maintaining their size ≈50-60 nm for an extended period. SeNPs demonstrate enhanced toxicity in cancer cell lines while sparing primary human dermal fibroblasts, underscoring their potential as effective anticancer agents. Moreover, the combination of BSA-SeNPs with a nanovaccine results in a strong tumor growth reduction in an EO771 breast cancer mouse model, demonstrating a three-fold decrease in tumor size. This synergistic anticancer effect not only highlights the role of SeNPs as effective anticancer agents but also offers valuable insights for developing innovative combinatorial approaches using SeNPs to improve the outcomes of cancer immunotherapy.

Nanocarrier design for pathogen-inspired innate immune agonist delivery

In complex diseases such as cancer, modulating cytokine signatures of disease using innate immune agonists holds therapeutic promise. Novel multi-agonist treatments offer tunable control of the immune system because they are uniquely pathogen inspired, eliciting robust antitumor responses by promoting synergistic cytokine responses. However, the chief strategic hurdle is ensuring multi-agonist delivery to the same target cells, highlighting the importance of using nanomaterial-based carriers. Here, we place nanocarriers in center stage and review the delivery hurdles related to the varying extra- and intracellular localizations of innate immune receptors. We discuss a range of nanomaterials used for multi-agonist delivery, highlighting their respective benefits and drawbacks. Our overarching stance is that rational nanocarrier design is crucial for developing pathogen-inspired multi-agonist immunotherapies.

Highly functionalized pH-triggered supramolecular nanovalve for targeted cancer chemotherapy

Chemotherapeutic drug delivery systems are commonly limited by their short half-lives, poor bioavailability, and unsuccessful targetability. Herein, pH-responsive hybrid NPs consist of benzimidazole-coated mesoporous silica nanoparticles (BZ-MSN) loaded with naturally occurring flavonoid quercetin (QUE-BZ-MSN). The NPs were further capped with beta-cyclodextrin (BCD) to obtain our desired BCD-QUE-BZMSN, with a zeta potential around 7.05 ± 2.37 mV and diameter about 115.2 ± 19.02 nm. The abundance of BZ onto the nanoparticles facilitates targeted quercetin chemotherapy against model lung and liver cancer cell lines. FTIR, EDX, and NMR analyses revealed evidence of possible surface functionalizations. Powder XRD analysis showed that our designed BCD-QUE-BZMSN formulation is amorphous in nature. The UV and SEM showed that our designed BCD-QUE-BZMSN has high drug entrapment efficiency and a nearly spherical morphology. In vitro, drug release assessments show controlled pH-dependent release profiles that could enhance the targeted chemotherapeutic response against mildly acidic regions in cancer cell lines. The obtained BCD-QUE-BZMSN nanovalve achieved significantly higher cytotoxic efficacy as compared to QUE alone, which was evaluated by in vitro cellular uptake against liver and lung cancer cell lines, and the cellular morphological ablation was further confirmed via inverted microscopy. The outcomes of the study imply that our designed BCD-QUE-BZMSN nanovalve is a potential carrier for cancer chemotherapeutics.

Advances in Peptide-Decorated Targeted Drug Delivery: Exploring Therapeutic Potential and Nanocarrier Strategies

Peptides are ideal biologicals for targeted drug delivery and have also been increasingly employed as theranostic tools in treating various diseases, including cancer, with minimal or no side effects. Owing to their receptor-specificity, peptide-mediated drug delivery aids in targeted drug delivery with better pharmacological biodistribution. Nanostructured self-assembled peptides and peptide-drug conjugates demonstrate enhanced stability and performance and captivating biological effects in comparison with conventional peptides. Moreover, they serve as valuable tools for establishing interfaces between drug carriers and biological systems, enabling the traversal of multiple biological barriers encountered by peptide-drug conjugates on their journeys to their intended targets. Peptide-based drugs play a pivotal role in the field of medicine and hold great promise for addressing a wide range of complex diseases such as cancer and autoimmune disorders. Nanotechnology has revolutionized the fields of medicine, biomedical engineering, biotechnology, and engineering sciences over the past two decades. With the help of nanotechnology, better delivery of peptides to the target site could be achieved by exploiting the small size, increased surface area, and passive targeting ability of the nanocarrier. Furthermore, nanocarriers also ensure safe delivery of the peptide moieties to the target site, protecting them from degradation. Nanobased peptide delivery systems would be of significant importance in the near future for the successful targeted and efficient delivery of peptides. This review focuses on peptide-drug conjugates and nanoparticle-mediated self-assembled peptide delivery systems in cancer therapeutics.

Core-Tunable Dendritic Polymer: A Folate-Guided Theranostic Nanoplatform for Drug Delivery Applications

Clinical application of anticancer drugs is mostly limited due to their hydrophobic nature, which often results in lower bioavailability and lesser retention in systemic circulation. Despite extensive research on the development of targeted drug delivery systems for cancer treatment, delivery of hydrophobic therapeutic drugs to tumor cells remains a major challenge in the field. To address these concerns, we have precisely engineered a new hyperbranched polymer for the targeted delivery of hydrophobic drugs by using a malonic acid-based A2B monomer and 1,6-hexanediol. The choice of monomer systems in our design allows for the formation of higher molecular weight polymers with hydrophobic cavities for the efficient encapsulation of therapeutic drugs that exhibit poor water solubility. Using several experimental techniques such as NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform-infrared (FT-IR), and gel permeation chromatography (GPC), the synthesized polymer was characterized, which indicated its dendritic structure, thermal stability, and amorphous nature, making it suitable as a drug delivery system. Following characterizations, theranostic nanoplatforms were formulated using a one-pot solvent diffusion method to coencapsulate hydrophobic drugs, BQU57 and doxorubicin. To achieve targeted delivery of loaded therapeutic drugs in A549 cancer cells, the surface of the polymeric nanoparticle was conjugated with folic acid. The therapeutic efficacy of the delivery system was determined by various cell-based in vitro experiments, including cytotoxicity, cell internalizations, reactive oxygen species (ROS), apoptosis, migration, and comet assays. Overall, findings from this study indicate that the synthesized dendritic polymer is a promising carrier for hydrophobic anticancer drugs with higher biocompatibility, stability, and therapeutic efficacy for applications in cancer therapy.

PEGose Block Poly(lactic acid) Nanoparticles for Cargo Delivery

Hydrophilic polymers have found ubiquitous use in drug delivery and novel polymer materials to advance drug delivery systems are highly sought after. Herein, an amylose mimic (PEGose) was combined with poly(lactic acid) (PLA) in an amphiphilic block copolymer to form PEG-free nanoparticles as an alternative to PEG-based nanomedicines. The block copolymer self-assembled into 150-200 nm particles with a narrow dispersity in aqueous environment. The formed nanoparticles were capable of encapsulation, the sustained release of both hydrophilic and hydrophobic dyes. Moreover, the nanoparticles were found to be remarkably stable and had a very low cytotoxicity and a high propensity to penetrate cells. These results highlight the potential of PEGose-b-PLA to be used in drug delivery with a new hydrophilic building block.

Development, characterization, and evaluation of withaferin-A and artesunate-loaded pH-responsive acetal-dextran polymeric nanoparticles for the management of malaria

Artemisinin and its derivatives have been commonly used to treat malaria. However, the emergence of resistance against artemisinin derivatives has posed a critical challenge in malaria management. In the present study, we have proposed a combinatorial approach, utilizing pH-responsive acetal-dextran nanoparticles (Ac-Dex NPs) as carriers for the delivery of withaferin-A (WS-3) and artesunate (Art) to improve treatment efficacy of malaria. The optimized WS-3 and Art Ac-Dex NPs demonstrated enhanced pH-responsive release profiles under parasitophorous mimetic conditions (pH 5.5). Computational molecular modeling reveals that Ac-Dex's polymeric backbone strongly interacts with merozoite surface protein-1 (MSP-1), preventing erythrocyte invasion. In-vitro antimalarial activity of drug-loaded Ac-Dex NPs reveals a 1-1.5-fold reduction in IC50 values compared to pure drug against the 3D7 strain of Plasmodium falciparum. Treatment with WS-3 Ac-Dex NPs (100 mg/kg) and Art Ac-Dex NPs (30 mg/kg) to Plasmodium berghei-infected mice resulted in 78.11 % and 100 % inhibition of parasitemia. Notably, the combination therapy comprised of Art and WS-3 Ac-Dex NPs achieved complete inhibition of parasitemia even at a half dose of Art, indicating the synergistic potential of the combinations. However, further investigations are necessary to confirm the safety and effectiveness of WS-3 and Art Ac-Dex NPs for their successful clinical implications.

Targeted pH-responsive delivery of rosmarinic acid via phenylboronic acid functionalized mesoporous silica nanoparticles for liver and lung cancer therapy

Currently, chemotherapy is one of the most practiced approaches for the treatment of cancers. However, existing chemotherapeutic drugs have poor aqueous solubility, poor selectivity, higher systematic toxicity, and poor target accumulation. In this study, we designed and synthesized a boronic acid/ester-based pH-responsive nano-valve that specifically targets the microenvironment in cancer cells. The nano-valve comprises phenylboronic acid-coated mesoporous silica nanoparticles (B-MSN) loaded with polyphenolic compound Rosmarinic acid (ROS-B-MSN). The nano-valve was further coated with lignin (LIG) to achieve our desired LIG-ROS-BMSN nano-valve for targeted chemotherapy against Hep-G2 and NCI-H460 cell lines. The structure and properties of NPs were characterized by Fourier-transformed infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) in combination with EDX, and Dynamic light scattering (DLS). The outcomes revealed that the designed LIG-ROS-BMSN were in the nanorange (144.1 ± 0.70 nm), had negative Zeta potential (-15.7 ± 0.46 mV) and had a nearly spherical morphology. In vitro, drug release investigations showed a controlled pH-dependent release profile under mild acidic conditions that could enhance the targeted chemotherapeutic response against cancer in mild acidic environments. The obtained LIG-ROS-BMSN nano valve achieved significantly lower IC50 values of (1.70 ± 0.01 μg/mL and 3.25 ± 0.14 μg/mL) against Hep-G2 and NCI-H460 cell lines as compared to ROS alone, which was (14.0 ± 0.7 μg/mL and 29.10 ± 0.25 μg/mL), respectively. The cellular morphology before and after treatment was further confirmed via inverted microscopy. The outcomes of the current study imply that our designed LIG-ROS-BMSN nanovalve is a potential carrier for cancer chemotherapeutics.

Tumor suppressor Par-4 activates autophagy-dependent ferroptosis

Ferroptosis is a unique iron-dependent form of non-apoptotic cell death characterized by devastating lipid peroxidation. Whilst growing evidence suggests that ferroptosis is a type of autophagy-dependent cell death, the underlying molecular mechanisms regulating ferroptosis are largely unknown. In this study, through an unbiased RNA-sequencing screening, we demonstrate the activation of a multi-faceted tumor-suppressor protein Par-4/PAWR during ferroptosis. Functional studies reveal that genetic depletion of Par-4 effectively blocks ferroptosis, whereas Par-4 overexpression sensitizes cells to undergo ferroptosis. More importantly, we have determined that Par-4-triggered ferroptosis is mechanistically driven by the autophagic machinery. Upregulation of Par-4 promotes activation of ferritinophagy (autophagic degradation of ferritin) via the nuclear receptor co-activator 4 (NCOA4), resulting in excessive release of free labile iron and, hence, enhanced lipid peroxidation and ferroptosis. Inhibition of Par-4 dramatically suppresses the NCOA4-mediated ferritinophagy signaling axis. Our results also establish that Par-4 activation positively correlates with reactive oxygen species (ROS) production, which is critical for ferritinophagy-mediated ferroptosis. Furthermore, Par-4 knockdown effectively blocked ferroptosis-mediated tumor suppression in the mouse xenograft models. Collectively, these findings reveal that Par-4 has a crucial role in ferroptosis, which could be further exploited for cancer therapy.

Application of Doxorubicin-loaded PLGA nanoparticles targeting both tumor cells and cancer-associated fibroblasts on 3D human skin equivalents mimicking melanoma and cutaneous squamous cell carcinoma

Nanoparticle (NP) use in cancer therapy is extensively studied in skin cancers. Cancer-associated fibroblasts (CAFs), a major tumor microenvironment (TME) component, promote cancer progression, making dual targeting of cancer cells and CAFs an effective therapy. However, dual NP-based targeting therapy on both tumor cells and CAFs is poorly investigated in skin cancers. Herein, we prepared and characterized doxorubicin-loaded PLGA NPs (DOX@PLGA NPs) and studied their anti-tumor effects on cutaneous melanoma (SKCM)(AN, M14) and cutaneous squamous cell carcinoma (cSCC) (MET1, MET2) cell lines in monolayer, as well as their impact on CAF deactivation. Then, we established 3D full thickness models (FTM) models of SKCM and cSCC using AN or MET2 cells on dermis matrix populated with CAFs respectively, and assessed the NPs' tumor penetration, tumor-killing ability, and CAF phenotype regulation through both topical administration and intradermal injection. The results show that, in monolayer, DOX@PLGA NPs inhibited cancer cell growth and induced apoptosis in a dose- and time-dependent manner, with a weaker effect on CAFs. DOX@PLGA NPs reduced CAF-marker expression and had successful anti-tumor effects in 3D skin cancer FTMs, with decreased tumor-load and invasion. DOX@PLGA NPs also showed great delivery potential in the FTMs and could be used as a platform for future functional study of NPs in skin cancers using human-derived skin equivalents. This study provides promising evidence for the potential of DOX@PLGA NPs in dual targeting therapy for SKCM and cSCC.

Reversal of cisplatin resistance in oral squamous cell carcinoma by piperlongumine loaded smart nanoparticles through inhibition of Hippo-YAP signaling pathway

Cisplatin alone or in combination with 5FU and docetaxel is the preferred chemotherapy regimen for advanced-stage OSCC patients. However, its use has been linked to recurrence and metastasis due to the development of drug resistance. Therefore, sensitization of cancer cells to conventional chemotherapeutics can be an effective strategy to overcome drug resistance. Piperlongumine (PL), an alkaloid, have shown anticancer properties and sensitizes numerous neoplasms, but its effect on OSCC has not been explored. However, low aqueous solubility and poor pharmacokinetics limit its clinical application. Therefore, to improve its therapeutic efficacy, we developed piperlongumine-loaded PLGA-based smart nanoparticles (smart PL-NPs) that can rapidly release PL in an acidic environment of cancer cells and provide optimum drug concentrations to overcome chemoresistance. Our results revealed that smart PL-NPs has high cellular uptake in acidic environment, facilitating the intracellular delivery of PL and sensitizing cancer cells to cisplatin, resulting in synergistic anticancer activity in vitro by increasing DNA damage, apoptosis, and inhibiting drug efflux. Further, we have mechanistically explored the Hippo-YAP signaling pathway, which is the critical mediator of chemoresistance, and investigated the chemosensitizing effect of PL in OSCC. We observed that PL alone and in combination with cisplatin significantly inhibits the activation of YAP and its downstream target genes and proteins. In addition, the combination of cisplatin with smart PL-NPs significantly inhibited tumor growth in two preclinical models (patient-derived cell based nude mice and zebrafish xenograft). Taken together, our findings suggest that smart PL-NPs with cisplatin will be a novel formulation to reverse cisplatin resistance in patients with advanced OSCC.

Harnessing the Power of Stimuli-Responsive Nanoparticles as an Effective Therapeutic Drug Delivery System

The quest for effective and reliable methods of delivering medications, with the aim of improving delivery of therapeutic agent to the intended location, has presented a demanding yet captivating field in biomedical research. The concept of smart drug delivery systems is an evolving therapeutic approach, serving as a model for directing drugs to specific targets or sites. These systems have been developed to specifically target and regulate the administration of therapeutic substances in a diverse array of chronic conditions, including periodontitis, diabetes, cardiac diseases, inflammatory bowel diseases, rheumatoid arthritis, and different cancers. Nevertheless, numerous comprehensive clinical trials are still required to ascertain both the immediate and enduring impacts of such nanosystems on human subjects. This review delves into the benefits of different drug delivery vehicles, aiming to enhance comprehension of their applicability in addressing present medical requirements. Additionally, it touches upon the current applications of these stimuli-reactive nanosystems in biomedicine and outlines future development prospects.

Biomaterial strategies for regulating the neuroinflammatory response

Injury and disease in the central nervous system (CNS) can result in a dysregulated inflammatory environment that inhibits the repair of functional tissue. Biomaterials present a promising approach to tackle this complex inhibitory environment and modulate the mechanisms involved in neuroinflammation to halt the progression of secondary injury and promote the repair of functional tissue. In this review, we will cover recent advances in biomaterial strategies, including nanoparticles, hydrogels, implantable scaffolds, and neural probe coatings, that have been used to modulate the innate immune response to injury and disease within the CNS. The stages of inflammation following CNS injury and the main inflammatory contributors involved in common neurodegenerative diseases will be discussed, as understanding the inflammatory response to injury and disease is critical for identifying therapeutic targets and designing effective biomaterial-based treatment strategies. Biomaterials and novel composites will then be discussed with an emphasis on strategies that deliver immunomodulatory agents or utilize cell-material interactions to modulate inflammation and promote functional tissue repair. We will explore the application of these biomaterial-based strategies in the context of nanoparticle- and hydrogel-mediated delivery of small molecule drugs and therapeutic proteins to inflamed nervous tissue, implantation of hydrogels and scaffolds to modulate immune cell behavior and guide axon elongation, and neural probe coatings to mitigate glial scarring and enhance signaling at the tissue-device interface. Finally, we will present a future outlook on the growing role of biomaterial-based strategies for immunomodulation in regenerative medicine and neuroengineering applications in the CNS.

Nanomaterials as Microglia Modulators in the Treatment of Central Nervous System Disorders

Microglia play a pivotal role in the central nervous system (CNS) homeostasis, acting as housekeepers and defenders of the surrounding environment. These cells can elicit their functions by shifting into two main phenotypes: pro-inflammatory classical phenotype, M1, and anti-inflammatory alternative phenotype, M2. Despite their pivotal role in CNS homeostasis, microglia phenotypes can influence the development and progression of several CNS disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, ischemic stroke, traumatic brain injuries, and even brain cancer. It is thus clear that the possibility of modulating microglia activation has gained attention as a therapeutic tool against many CNS pathologies. Nanomaterials are an unprecedented tool for manipulating microglia responses, in particular, to specifically target microglia and elicit an in situ immunomodulation activity. This review focuses the discussion on two main aspects: analyzing the possibility of using nanomaterials to stimulate a pro-inflammatory response of microglia against brain cancer and introducing nanostructures able to foster an anti-inflammatory response for treating neurodegenerative disorders. The final aim is to stimulate the analysis of the development of new microglia nano-immunomodulators, paving the way for innovative and effective therapeutic approaches for the treatment of CNS disorders.

Harnessing Microbial Effectors for Macrophage-Mediated Drug Delivery

Macrophage-based drug delivery systems are promising, but their development is still in its infancy, with many limitations remaining to be addressed. Our aim was to design a system harnessing microbial effectors to facilitate controlled drug cargo expulsion from macrophages to enable the use of more toxic drugs without adding to the risk of off-target detrimental effects. The pore forming and actin polymerizing Listeria monocytogenes effectors listeriolysin-O (LLO) and actin assembly-inducing protein (ActA) were synthesized using a novel green fluorescent protein (GFP)-linked heterologous expression system. These effectors were coated onto polystyrene beads to generate "synthetic cargo" before loading into primary M1 macrophages. Bead uptake and release from macrophages were evaluated by using high-throughput quantitative imaging flow cytometry and confocal microscopy. In vitro results confirmed appropriate activity of synthesized effectors. Coating of these effector proteins onto polystyrene beads (simulated drug cargo) resulted in changes in cellular morphology, bead content, and intracellular bead localization, which may support an interpretation of the induced release of these beads from the cells. This forms the basis for further investigation to fully elucidate any potential release mechanisms. Bacterial effectors ActA and LLO successfully effectuated actin polarization and protrusions from cell membranes similar to those seen in cells infected with Listeria spp., illustrating the potential of using these effectors and production methods for the development of an endogenous drug delivery system capable of low-risk, targeted release of high potency drugs.

Biomaterials for Protein Delivery: Opportunities and Challenges to Clinical Translation

The development of biomaterials for protein delivery is an emerging field that spans materials science, bioengineering, and medicine. In this review, we highlight the immense potential of protein-delivering biomaterials as therapeutic options and discuss the multifaceted challenges inherent to the field. We address current advancements and approaches in protein delivery that leverage stimuli-responsive materials, harness advanced fabrication techniques like 3D printing, and integrate nanotechnologies for greater targeting and improved stability, efficacy, and tolerability profiles. We also discuss the demand for highly complex delivery systems to maintain structural integrity and functionality of the protein payload. Finally, we discuss barriers to clinical translation, such as biocompatibility, immunogenicity, achieving reliable controlled release, efficient and targeted delivery, stability issues, scalability of production, and navigating the regulatory landscape for such materials. Overall, this review summarizes insights from a survey of the current literature and sheds light on the interplay between innovation and the practical implementation of biomaterials for protein delivery.

Precision Loading and Delivery of Molecular Cargo by Size-Controlled Coacervation of Gold Nanoparticles Functionalized with Elastin-like Peptides

Thermoresponsive elastin-like peptides (ELPs) have been extensively investigated in biotechnology and medicine, but little attention has been paid to the process by which coacervation causes ELP-decorated particles to aggregate. Using gold nanoparticles (AuNPs) functionalized with a cysteine-terminated 96-repeat of the VPGVG sequence (V96-Cys), we show that the size of the clusters that reversibly form above the ELP transition temperature can be finely controlled in the 250 to 930 nm range by specifying the concentration of free V96-Cys in solution and using AuNPs of different sizes. We further find that the localized surface plasmon resonance peak of the embedded AuNPs progressively red-shifts with cluster size, likely due to an increase in particle-particle contacts. We exploit this fine control over size to homogeneously load precise amounts of the dye Nile Red and the antibiotic Tetracycline into clusters of different hydrodynamic diameters and deliver cargos near-quantitatively by deconstructing the aggregates below the ELP transition temperature. Beyond establishing a key role for free ELPs in the agglomeration of ELP-functionalized particles, our results provide a path for the thermally controlled delivery of precise quantities of molecular cargo. This capability might prove useful in combination photothermal therapies and theranostic applications, and to trigger spatially and temporally uniform responses from biological, electronic, or optical systems.

Bacteria for Bioplastics: Progress, Applications, and Challenges

Bioplastics are one of the answers that can point society toward a sustainable future. Under this premise, the synthesis of polymers with competitive properties using low-cost starting materials is a highly desired factor in the industry. Also, tackling environmental issues such as nonbiodegradable waste generation, high carbon footprint, and consumption of nonrenewable resources are some of the current concerns worldwide. The scientific community has been placing efforts into the biosynthesis of polymers using bacteria and other microbes. These microorganisms can be convenient reactors to consume food and agricultural wastes and convert them into biopolymers with inherently attractive properties such as biodegradability, biocompatibility, and appreciable mechanical and chemical properties. Such biopolymers can be applied to several fields such as packing, cosmetics, pharmaceutical, medical, biomedical, and agricultural. Thus, intending to elucidate the science of microbes to produce polymers, this review starts with a brief introduction to bioplastics by describing their importance and the methods for their production. The second section dives into the importance of bacteria regarding the biochemical routes for the synthesis of polymers along with their advantages and disadvantages. The third section covers some of the main parameters that influence biopolymers' production. Some of the main applications of biopolymers along with a comparison between the polymers obtained from microorganisms and the petrochemical-based ones are presented. Finally, some discussion about the future aspects and main challenges in this field is provided to elucidate the main issues that should be tackled for the wide application of microorganisms for the preparation of bioplastics.

Near infra-red absorbing Quinolizidine fused curcuminoid-BF2 chelate and its applications in photodynamic therapy using MCF-7 and A549 cells

Metal-free near-infrared absorbing photosensitizers (PS) have been considered promising candidates for photodynamic therapy. Curcumin, curcuminoid, and its derivatives have therapeutic values due to their anti-inflammatory, antifungal, and antiproliferative properties. Curcuminoid-BF2 chelates have also been studied as cell imaging probes, however, their applications in photodynamic therapy are rare. In this article, we describe the synthesis and therapeutic evaluation of quinolizidine fused curcuminoid-BF2 chelate (Quinolizidine CUR-BF2) containing an acid-sensitive group. This donor-acceptor-donor curcuminoid-BF2 derivative exhibits absorption and emission in the deep red region with an absorption band maximum of ∼647 nm and a weak emission band at approximately 713 nm. It is interesting to note that this derivative has a high molar extinction coefficient (164,655 M-1cm-1). Quinolizidine CUR-BF2 possesses intramolecular charge transfer properties, facilitating the production of singlet oxygen (1O2), which plays a crucial role in cell death. Additionally, Quinolizidine CUR-BF2 can enable the selective release of active ingredients in an acidic medium (pH 5). Furthermore, the nanoaggregates of PS were prepared by encapsulating Quinolizidine CUR-BF2 within Pluronic F127 block co-polymer for better water-dispersibility and enhanced cellular uptake. Dark cytotoxicity of nanoaggregates was found to be negligible, whereas they exhibited significant photoinduced cytotoxicity towards cancer cells (MCF-7 and A549) under irradiation of 635 nm light. Further, the cell death pathway using Quinolizidine CUR-BF2 nanoaggregates as PS is found to occur through apoptosis. Specifically, the present study deals with the successful preparation of Quinolizidine CUR-BF2 nanoaggregates for enhanced water-dispersibility and cellular uptake as well as the efficacy evaluation of developed nanoaggregates for photodynamic therapy.

A pH-Responsive Virus-Like Particle as a Protein Cage for a Targeted Delivery

A stimuli-responsive protein self-assembly offers promising utility as a protein nanocage for biotechnological and medical applications. Herein, the development of a virus-like particle (VLP) that undergoes a transition between assembly and disassembly under a neutral and acidic pH, respectively, for a targeted delivery is reported. The structure of the bacteriophage P22 coat protein is used for the computational design of coat subunits that self-assemble into a pH-responsive VLP. Subunit designs are generated through iterative computational cycles of histidine substitutions and evaluation of the interaction energies among the subunits under an acidic and neutral pH. The top subunit designs are tested and one that is assembled into a VLP showing the highest pH-dependent structural transition is selected. The cryo-EM structure of the VLP is determined, and the structural basis of a pH-triggered disassembly is delineated. The utility of the designed VLP is exemplified through the targeted delivery of a cytotoxic protein cargo into tumor cells in a pH-dependent manner. These results provide strategies for the development of self-assembling protein architectures with new functionality for diverse applications.

Biomaterial-Based Responsive Nanomedicines for Targeting Solid Tumor Microenvironments

Solid tumors are composed of a highly complex and heterogenic microenvironment, with increasing metabolic status. This environment plays a crucial role in the clinical therapeutic outcome of conventional treatments and innovative antitumor nanomedicines. Scientists have devoted great efforts to conquering the challenges of the tumor microenvironment (TME), in respect of effective drug accumulation and activity at the tumor site. The main focus is to overcome the obstacles of abnormal vasculature, dense stroma, extracellular matrix, hypoxia, and pH gradient acidosis. In this endeavor, nanomedicines that are targeting distinct features of TME have flourished; these aim to increase site specificity and achieve deep tumor penetration. Recently, research efforts have focused on the immune reprograming of TME in order to promote suppression of cancer stem cells and prevention of metastasis. Thereby, several nanomedicine therapeutics which have shown promise in preclinical studies have entered clinical trials or are already in clinical practice. Various novel strategies were employed in preclinical studies and clinical trials. Among them, nanomedicines based on biomaterials show great promise in improving the therapeutic efficacy, reducing side effects, and promoting synergistic activity for TME responsive targeting. In this review, we focused on the targeting mechanisms of nanomedicines in response to the microenvironment of solid tumors. We describe responsive nanomedicines which take advantage of biomaterials' properties to exploit the features of TME or overcome the obstacles posed by TME. The development of such systems has significantly advanced the application of biomaterials in combinational therapies and in immunotherapies for improved anticancer effectiveness.

Anti-tumor effect of pH-sensitive drug-loaded nanoparticles optimized via an integrated computational/experimental approach

The acidic pH of tumor tissue has been used to trigger drug release from nanoparticles. However, dynamic interactions between tumor pH and vascularity present challenges to optimize therapy to particular microenvironment conditions. Despite recent development of pH-sensitive nanomaterials that can accurately quantify drug release from nanoparticles, tailoring release to maximize tumor response remains elusive. This study hypothesizes that a computational modeling-based platform that simulates the heterogeneously vascularized tumor microenvironment can enable evaluation of the complex intra-tumoral dynamics involving nanoparticle transport and pH-dependent drug release, and predict optimal nanoparticle parameters to maximize the response. To this end, SPNCD nanoparticles comprising superparamagnetic cores of iron oxide (Fe3O4) and a poly(lactide-co-glycolide acid) shell loaded with doxorubicin (DOX) were fabricated. Drug release was measured in vitro as a function of pH. A 2D model of vascularized tumor growth was calibrated to experimental data and used to evaluate SPNCD effect as a function of drug release rate and tissue vascular heterogeneity. Simulations show that pH-dependent drug release from SPNCD delays tumor regrowth more than DOX alone across all levels of vascular heterogeneity, and that SPNCD significantly inhibit tumor radius over time compared to systemic DOX. The minimum tumor radius forecast by the model was comparable to previous in vivo SPNCD inhibition data. Sensitivity analyses of the SPNCD pH-dependent drug release rate indicate that slower rates are more inhibitory than faster rates. We conclude that an integrated computational and experimental approach enables tailoring drug release by pH-responsive nanomaterials to maximize the tumor response.

pH/redox responsive size-switchable intelligent nanovehicle for tumor microenvironment targeted DOX release

Tumor microenvironment (TME) targeted strategy could control the drug release in tumor cells more accurately and creates a new opportunity for enhanced site-specific targeted delivery. In this study, (PAA-b-PCL-S-S-PCL-b-PAA) copolymeric nanoparticles (NPs) with size-switchable ability and dual pH/redox-triggered drug release behavior were designed to significantly promote cancer uptake (cell internalization of around 100% at 30 min) and site-specific targeted doxorubicin (DOX) delivery in MDA-MB-231 tumor cells. NPs surface charge was shifted from - 17.8 to - 2.4 and their size shrunk from 170.3 to 93 nm in TME. The cell cycle results showed that DOX-loaded NPs showed G2/M (68%) arrest, while free DOX showed sub-G1 arrest (22%). Apoptosis tests confirmed that the cells treated with DOX-loaded NPs showed a higher amount of apoptosis (71.6%) than the free DOX (49.8%). Western blot and RT-PCR assays revealed that the apoptotic genes and protein levels were significantly upregulated using the DOX-loaded NPs vs. the free DOX (Pvalue < 0.001). In conclusion, dual pH/redox-responsive and size-switchable DOX-loaded NPs developed here showed outstanding anti-tumoral features compared with free DOX that might present a prospective platform for tumor site-specific accumulation and drug release that suggest further in vivo research.

Smart chemistry for traceless release of anticancer therapeutics

In the design of delivery strategies for anticancer therapeutics, the controlled release of intact cargo at the destined tumor and metastasis locations is of particular importance. To this end, stimuli-responsive chemical linkers have been extensively investigated owing to their ability to respond to tumor-specific physiological stimuli, such as lowered pH, altered redox conditions, increased radical oxygen species and pathological enzymatic activities. To prevent premature action and off-target effects, anticancer therapeutics are chemically modified to be transiently inactivated, a strategy known as prodrug development. Prodrugs are reactivated upon stimuli-dependent release at the sites of interest. As most drugs and therapeutic proteins have the optimal activity when released from carriers in their native and original forms, traceless release mechanisms are increasingly investigated. In this review, we summarize the chemical toolkit for developing innovative traceless prodrug strategies for stimuli-responsive drug delivery and discuss the applications of these chemical modifications in anticancer treatment including cancer immunotherapy.

A selenoureido-iminoglycolipid transported by zeolitic-imidazolate framework nanoparticles: a novel antioxidant therapeutic approach

A selenium-containing metal-organic framework with remarkable antioxidant capacity and ROS-scavenging activity was constructed by a controlled de novo encapsulation approach of a glycoconjugate mimetic, specifically a sp2-iminoglycolipid bearing a selenoureido fragment (DSeU), within a zeolitic-imidazolate framework exoskeleton. Biocompatible and homogeneous nanosized particles of ∼70 nm (DSeU@ZIF8) were obtained, which could be efficiently internalized in cells, overcoming the poor solubility in biological media and limited bioavailability of glycolipids. The ZIF-particle served as nanocarrier for the intracellular delivery of the selenocompound to cells, promoted by the acidic pH inside endosomes/lysosomes. As demonstrated by in vitro studies, the designed DSeU@ZIF8 nanoparticles displayed a high antioxidant activity at low doses; lower intracellular ROS levels were observed upon the uptake of DSeU@ZIF8 by human endothelial cells. Even more interesting was the finding that these DSeU@ZIF8 particles were able to reverse to a certain level the oxidative stress induced in cells by pre-treatment with an oxidizing agent. This possibility of modulating the oxidative stress in living cells may have important implications in the treatment of diverse pathological complications that are generally accompanied with elevated ROS levels.

Positive regulation of oxidative phosphorylation by nuclear myosin 1 protects cells from metabolic reprogramming and tumorigenesis in mice

Metabolic reprogramming is one of the hallmarks of tumorigenesis. Here, we show that nuclear myosin 1 (NM1) serves as a key regulator of cellular metabolism. NM1 directly affects mitochondrial oxidative phosphorylation (OXPHOS) by regulating mitochondrial transcription factors TFAM and PGC1α, and its deletion leads to underdeveloped mitochondria inner cristae and mitochondrial redistribution within the cell. These changes are associated with reduced OXPHOS gene expression, decreased mitochondrial DNA copy number, and deregulated mitochondrial dynamics, which lead to metabolic reprogramming of NM1 KO cells from OXPHOS to aerobic glycolysis.This, in turn, is associated with a metabolomic profile typical for cancer cells, namely increased amino acid-, fatty acid-, and sugar metabolism, and increased glucose uptake, lactate production, and intracellular acidity. NM1 KO cells form solid tumors in a mouse model, suggesting that the metabolic switch towards aerobic glycolysis provides a sufficient carcinogenic signal. We suggest that NM1 plays a role as a tumor suppressor and that NM1 depletion may contribute to the Warburg effect at the onset of tumorigenesis.

pH-Responsive Upconversion Mesoporous Silica Nanospheres for Combined Multimodal Diagnostic Imaging and Targeted Photodynamic and Photothermal Cancer Therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) have gained considerable attention as potential alternatives to conventional cancer treatments. However, these approaches remain limited by low solubility, poor stability, and inefficient targeting of many common photosensitizers (PSs) and photothermal agents (PTAs). To overcome the aforementioned limitations, we engineered biocompatible and biodegradable tumor-targeted upconversion nanospheres with imaging capabilities. The multifunctional nanospheres consist of a sodium yttrium fluoride core doped with lanthanides (ytterbium, erbium, and gadolinium) and the PTA bismuth selenide (NaYF4:Yb/Er/Gd,Bi2Se3) enveloped in a mesoporous silica shell that encapsulates a PS, chlorin e6 (Ce6), within its pores. NaYF4:Yb/Er converts deeply penetrating near-infrared (NIR) light to visible light, which excites Ce6 to generate cytotoxic reactive oxygen species (ROS), while Bi2Se3 efficiently converts absorbed NIR light to heat. Additionally, Gd enables magnetic resonance imaging of the nanospheres. The mesoporous silica shell is coated with DPPC/cholesterol/DSPE-PEG to retain the encapsulated Ce6 and prevent serum protein adsorption and macrophage recognition that hinder tumor targeting. Finally, the coat is conjugated to the acidity-triggered rational membrane (ATRAM) peptide, which promotes specific and efficient internalization into malignant cells in the mildly acidic microenvironment of tumors. The nanospheres facilitated tumor magnetic resonance and thermal and fluorescence imaging and exhibited potent NIR laser light-induced anticancer effects in vitro and in vivo via combined ROS production and localized hyperthermia, with negligible toxicity to healthy tissue, hence markedly extending survival. Our results demonstrate that the ATRAM-functionalized, lipid/PEG-coated upconversion mesoporous silica nanospheres (ALUMSNs) offer multimodal diagnostic imaging and targeted combinatorial cancer therapy.

Lipid polymer hybrid nanoparticles: a custom-tailored next-generation approach for cancer therapeutics

Lipid-based polymeric nanoparticles are the highly popular carrier systems for cancer drug therapy. But presently, detailed investigations have revealed their flaws as drug delivery carriers. Lipid polymer hybrid nanoparticles (LPHNPs) are advanced core-shell nanoconstructs with a polymeric core region enclosed by a lipidic layer, presumed to be derived from both liposomes and polymeric nanounits. This unique concept is of utmost importance as a combinable drug delivery platform in oncology due to its dual structured character. To add advantage and restrict one's limitation by other, LPHNPs have been designed so to gain number of advantages such as stability, high loading of cargo, increased biocompatibility, rate-limiting controlled release, and elevated drug half-lives as well as therapeutic effectiveness while minimizing their drawbacks. The outer shell, in particular, can be functionalized in a variety of ways with stimuli-responsive moieties and ligands to provide intelligent holding and for active targeting of antineoplastic medicines, transport of genes, and theragnostic. This review comprehensively provides insight into recent substantial advancements in developing strategies for treating various cancer using LPHNPs. The bioactivity assessment factors have also been highlighted with a discussion of LPHNPs future clinical prospects.

Dopamine-Conjugated Bovine Serum Albumin Nanoparticles Containing pH-Responsive Catechol-V(III) Coordination for In Vitro and In Vivo Drug Delivery

V(III) instead of commonly used Fe(III) provided a rich tris-catechol-metal coordination at pH 7.4, which is important for slow drug release at physiological pH. Bovine serum albumin (BSA) functionalized with catechol-containing dopamine (D) and cross-linked using tris-catechol-V(III) coordination yielded pH-responsive compact D-BSA NPs (253 nm). However, conversion to bis- and/or mono-catechol-V(III) complexes in an acidic medium resulted in degradation of NPs and rapid release of doxorubicin (DOX). It was shown that D-BSA NPs entered cancerous MCF-7 cells (66%) more efficiently than non-cancerous HEK293T (33%) in 3 h. Also, DOX-loaded NPs reduced cell viability of MCF-7 by 75% and induced apoptosis in a majority of cells after 24 h. Biodegradability and lack of hemolytic activity were shown in vitro, whereas a lack of toxicity was shown in histological sections of zebrafish. Furthermore, 30% of circulating tumor cells in vasculature in 24 h were killed by DOX-loaded NPs shown with the zebrafish CTC xenograft model.

Surface-Modified Biobased Polymeric Nanoparticles for Dual Delivery of Doxorubicin and Gefitinib in Glioma Cell Lines

Glioma is a malignant form of brain cancer that is challenging to treat due to the progressive growth of glial cells. To target overexpressed folate receptors in glioma brain tumors, we designed and investigated doxorubicin-gefitinib nanoparticles (Dox-Gefit NPs) and folate conjugated Dox-Gefit NPs (Dox-Gefit NPs-F). Dox-Gefit NPs and Dox-Gefit NPs-F were characterized by multiple techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), proton nuclear magnetic resonance (1H NMR), and transmission electron microscopy (TEM). In vitro release profiles were measured at both physiological and tumor endosomal pH. The cytotoxicity of the Dox-Gefit NP formulations was measured against C6 and U87 glioma cell lines. A hemolysis assay was performed to investigate biocompatibility of the formulations, and distribution of the drugs in different organs was also estimated. The Dox-Gefit NPs and Dox-Gefit NPs-F were 109.45 ± 7.26 and 120.35 ± 3.65 nm in size and had surface charges of -18.0 ± 3.27 and -20.0 ± 8.23 mV, respectively. Dox-Gefit NPs and Dox-Gefit NPs-F significantly reduced the growth of U87 cells, with IC50 values of 9.9 and 3.2 μM. Similarly, growth of the C6 cell line was significantly reduced, with IC50 values of 8.43 and 3.31 μM after a 24 h incubation, in Dox-Gefit NPs and Dox-Gefit NPs-F, respectively. The percentage drug releases of Dox and Gefit from Dox-Gefit NPs at pH 7.4 were 60.87 ± 0.59 and 68.23 ± 0.1%, respectively. Similarly, at pH 5.4, Dox and Gefit releases from NPs were 70.87 ± 0.28 and 69.24 ± 0.12%, respectively. Biodistribution analysis revealed that more Dox and Gefit were present in the brain than in the other organs. The functionalized NPs inhibited the growth of glioma cells due to high drug concentrations in the brain. Folate conjugated NPs of Dox-Gefit could be a treatment option in glioma therapy.

Functionalized nanozyme with drug loading for enhanced tumour combination treatment of catalytic therapy and chemotherapy

Nanozyme-based tumour catalytic therapy has attracted widespread attention in recent years, but the therapeutic efficacy is limited due to the trapping of hydroxyl radicals (˙OH) by endogenous glutathione (GSH) in the tumour microenvironment (TME). Zr/Ce-MOFs/DOX/MnO2 is constructed in this work to serve as a new kind of nanozyme for combination chemotherapy and catalytic treatment. Zr/Ce-MOFs can produce ˙OH in a mimic TME, and the MnO2 on the surface could deplete the GSH, further promoting the ˙OH generation. The pH/GSH dual stimulation accelerates the release of anticancer drug doxorubicin (DOX) in tumour tissue for enhanced tumour chemotherapy. Moreover, Mn2+ produced by the reaction of Zr/Ce-MOFs/DOX/MnO2 and GSH can be used as the contrast agent for T1-MRI. The potential antitumour effect of Zr/Ce-MOFs/DOX/MnO2 is demonstrated by in vitro and in vivo cancer treatment tests. This work thus provides a new nanozyme-based platform for enhanced combination chemotherapy and catalytic treatment for tumours.

PCL/gelatin nanofibers embedded with doxorubicin-loaded mesoporous silica nanoparticles/silver nanoparticles as an antibacterial and anti-melanoma cancer

Melanoma cancer wound healing is critical and complex and poses a significant challenge to researchers. Drug resistance, adverse side effects, and inefficient localization of chemotherapeutic drugs limit common treatment strategies in melanoma cancer. Using drug delivery nanostructures with low side effects and high efficiency, besides having antibacterial and antiseptic properties, can effectively repair the damage caused by the disease. To this end, this study aimed to develop a drug delivery nanosystem based on doxorubicin (DOX)-loaded amine-functionalized mesoporous silica nanoparticles (MSNs), linked with green synthesized silver nanoparticles (AgNPs). Characterization methods including microscopic methods and X-ray diffraction (XRD) confirmed the synthesis and functionalization of the well-dispersed nanoparticles with nanosized and uniform structures. The poly(ε-caprolactone) (PCL) nanofibers as a strong scaffold were produced by the blow spinning method and DOX-loaded nanoparticles were blow spun on PCL nanofibers along with gelatin solution. The resulting nanosystem including nanofibers and nanoparticles (NFs/NPS) showed a fine loading percent with a proper release profile of DOX and AgNPs and low hemolysis activity. Moreover, besides preventing infection by AgNPs, the DOX-loaded NFs/NPs could effectively destroy melanoma cancer cells. The attachment of normal cells to the nanoparticles-loaded nanofibers scaffold revealed the possibility of healing wounds caused by melanoma cancer.

Selective Blood Cell Hitchhiking in Whole Blood with Ionic Liquid-Coated PLGA Nanoparticles to Redirect Biodistribution After Intravenous Injection

Less than 5% of intravenously-injected nanoparticles (NPs) reach destined sites in the body due to opsonization and immune-based clearance in vascular circulation. By hitchhiking in situ onto specific blood components post-injection, NPs can selectively target tissue sites for unprecedentedly high drug delivery rates. Choline carboxylate ionic liquids (ILs) are biocompatible liquid salts <100X composed of bulky asymmetric cations and anions. This class of ILs has been previously shown to significantly extend circulation time and redirect biodistribution in BALB/c mice post-IV injection via hitchhiking on red blood cell (RBC) membranes. Herein, we synthesized & screened 60 choline carboxylic acid-based ILs to coat PLGA NPs and present the impact of structurally engineering the coordinated anion identity to selectively interface and hitchhike lymphocytes, monocytes, granulocytes, platelets, and RBCs in whole mouse blood for in situ targeted drug delivery. Furthermore, we find this nanoparticle platform to be biocompatible (non-cytotoxic), translate to human whole blood by resisting serum uptake and maintaining modest hitchhiking, and also significantly extend circulation retention over 24 hours in BALB/c healthy adult mice after IV injection. Because of their altered circulation profiles, we additionally observe dramatically different organ accumulation profiles compared to bare PLGA NPs. This study establishes an initial breakthrough platform for a modular and transformative targeting technology to hitchhike onto blood components with high efficacy and safety in the bloodstream post-IV administration.

Macrophage Cell Membrane Coating on Piperine-Loaded MIL-100(Fe) Nanoparticles for Breast Cancer Treatment

Piperine (PIP), a compound found in Piper longum, has shown promise as a potential chemotherapeutic agent for breast cancer. However, its inherent toxicity has limited its application. To overcome this challenge, researchers have developed PIP@MIL-100(Fe), an organic metal-organic framework (MOF) that encapsulates PIP for breast cancer treatment. Nanotechnology offers further treatment options, including the modification of nanostructures with macrophage membranes (MM) to enhance the evasion of the immune system. In this study, the researchers aimed to evaluate the potential of MM-coated MOFs encapsulated with PIP for breast cancer treatment. They successfully synthesized MM@PIP@MIL-100(Fe) through impregnation synthesis. The presence of MM coating on the MOF surface was confirmed through SDS-PAGE analysis, which revealed distinct protein bands. Transmission electron microscopy (TEM) images demonstrated the existence of a PIP@MIL-100(Fe) core with a diameter of around 50 nm, surrounded by an outer lipid bilayer layer measuring approximately 10 nm in thickness. Furthermore, the researchers evaluated the cytotoxicity indices of the nanoparticles against various breast cancer cell lines, including MCF-7, BT-549, SKBR-3, and MDA. The results demonstrated that the MOFs exhibited between 4 and 17 times higher cytotoxicity (IC₅₀) in all four cell lines compared to free PIP (IC₅₀ = 193.67 ± 0.30 µM). These findings suggest that MM@PIP@MIL-100(Fe) holds potential as an effective treatment for breast cancer. The study's outcomes highlight the potential of utilizing MM-coated MOFs encapsulated with PIP as an innovative approach for breast cancer therapy, offering improved cytotoxicity compared to free PIP alone. Further research and development are warranted to explore the clinical translation and optimize the efficacy and safety of this treatment strategy.

Targeting Wnt/β-catenin signaling using XAV939 nanoparticles in tumor microenvironment-conditioned macrophages promote immunogenicity

The aberrant activation of Wnt/β-catenin signaling in tumor cells and immune cells in the tumor microenvironment (TME) promotes malignant transformation, metastasis, immune evasion, and resistance to cancer treatments. The increased Wnt ligand expression in TME activates β-catenin signaling in antigen (Ag)-presenting cells (APCs) and regulates anti-tumor immunity. Previously, we showed that activation of Wnt/β-catenin signaling in dendritic cells (DCs) promotes induction of regulatory T cell responses over anti-tumor CD4⁺ and CD8⁺ effector T cell responses and promotes tumor progression. In addition to DCs, tumor-associated macrophages (TAMs) also serve as APCs and regulate anti-tumor immunity. However, the role of β-catenin activation and its effect on TAM immunogenicity in TME is largely undefined. In this study, we investigated whether inhibiting β-catenin in TME-conditioned macrophages promotes immunogenicity. Using nanoparticle formulation of XAV939 (XAV-Np), a tankyrase inhibitor that promotes β-catenin degradation, we performed in vitro macrophage co-culture assays with melanoma cells (MC) or melanoma cell supernatants (MCS) to investigate the effect on macrophage immunogenicity. We show that XAV-Np-treatment of macrophages conditioned with MC or MCS significantly upregulates the cell surface expression of CD80 and CD86 and suppresses the expression of PD-L1 and CD206 compared to MC or MCS-conditioned macrophages treated with control nanoparticle (Con-Np). Further, XAV-Np-treated macrophages conditioned with MC or MCS significantly increased IL-6 and TNF-α production, with reduced IL-10 production compared to Con-Np-treated macrophages. Moreover, the co-culture of MC and XAV-Np-treated macrophages with T cells resulted in increased CD8⁺ T cell proliferation compared to Con-Np-treated macrophages. These data suggest that targeted β-catenin inhibition in TAMs represents a promising therapeutic approach to promote anti-tumor immunity.

Peptide-Based Nanoparticles for Systemic Extrahepatic Delivery of Therapeutic Nucleotides

Peptide-based nanoparticles (PBN) for nucleotide complexation and targeting of extrahepatic diseases are gaining recognition as potent pharmaceutical vehicles for fine-tuned control of protein production (up- and/or down-regulation) and for gene delivery. Herein, we review the principles and mechanisms underpinning self-assembled formation of PBN, cellular uptake, endosomal release, and delivery to extrahepatic disease sites after systemic administration. Selected examples of PBN that have demonstrated recent proof of concept in disease models in vivo are summarized to offer the reader a comparative view of the field and the possibilities for clinical application.

Current Principles, Challenges, and New Metrics in pH-Responsive Drug Delivery Systems for Systemic Cancer Therapy

The paradigm of drug delivery via particulate formulations is one of the leading ideas that enable overcoming limitations of traditional chemotherapeutic agents. The trend toward more complex multifunctional drug carriers is well-traced in the literature. Nowadays, the prospectiveness of stimuli-responsive systems capable of controlled cargo release in the lesion nidus is widely accepted. Both endogenous and exogenous stimuli are employed for this purpose; however, endogenous pH is the most common trigger. Unfortunately, scientists encounter multiple challenges on the way to the implementation of this idea related to the vehicles' accumulation in off-target tissues, their immunogenicity, the complexity of drug delivery to intracellular targets, and finally, the difficulties in the fabrication of carriers matching all imposed requirements. Here, we discuss fundamental strategies for pH-responsive drug delivery, as well as limitations related to such carriers' application, and reveal the main problems, weaknesses, and reasons for poor clinical results. Moreover, we attempted to formulate the profiles of an "ideal" drug carrier in the frame of different strategies drawing on the example of metal-comprising materials and considered recently published studies through the lens of these profiles. We believe that this approach will facilitate the formulation of the main challenges facing researchers and the identification of the most promising trends in technology development.

Delivery of Chemotherapy Agents and Nucleic Acids with pH-Dependent Nanoparticles

With less than one percent of systemically injected nanoparticles accumulating in tumors, several novel approaches have been spurred to direct and release the therapy in or near tumors. One such approach depends on the acidic pH of the extracellular matrix and endosomes of the tumor. With an average pH of 6.8, the extracellular tumor matrix provides a gradient for pH-responsive particles to accumulate, enabling greater specificity. Upon uptake by tumor cells, nanoparticles are further exposed to lower pHs, reaching a pH of 5 in late endosomes. Based on these two acidic environments in the tumor, various pH-dependent targeting strategies have been employed to release chemotherapy or the combination of chemotherapy and nucleic acids from macromolecules such as the keratin protein or polymeric nanoparticles. We will review these release strategies, including pH-sensitive linkages between the carrier and hydrophobic chemotherapy agent, the protonation and disruption of polymeric nanoparticles, an amalgam of these first two approaches, and the release of polymers shielding drug-loaded nanoparticles. While several pH-sensitive strategies have demonstrated marked antitumor efficacy in preclinical trials, many studies are early in their development with several obstacles that may limit their clinical use.

Effect of size and morphology of functionalized upconversion nanoparticle labeled probe on stem cell absorption

In order to improve the application of stem cell therapy, it is important to monitor the proliferation and differentiation of transplanted stem cells in real time, high sensitivity and high precision. Upconversion nanoparticles (UCNPs) have been employed as bioimaging agents and delivery vehicles for gene therapeutics in several types of cells. Herein, we fabricated multiple functional upconversion nanoparticles (FUC-NPs) as exogenous contrast agents to investigate the effect of FUC-NPs size on the efficiency of tracking human umbilical cord mesenchymal stem cells (HUCMSCs). We used TEM, DLS, MTT, etc. systematically detected the effects of nanoparticle dose and exposure time on HUCMSCs cytotoxicity. Our data showed that incubation of FUC-NPs, HUCMSCs are able to maintain their viability and differentiation ability. Interestingly, the small size FUC-NPs examined, S-FUCs, had a much higher uptake capability than the other FUC-NPs (B-FUCs, H-FUCs and R-FUCs).The study will aid in UCNPs for the engineering of stem cell application in the future.

Stimuli-responsive drug delivery systems triggered by intracellular or subcellular microenvironments

Drug delivery systems (DDS) triggered by local microenvironment represents the state-of-art of nanomedicine design, where the triggering hallmarks at intracellular and subcellular levels could be employed to exquisitely recognize the diseased sites, reduce side effects, and expand the therapeutic window by precisely tailoring the drug-release kinetics. Though with impressive progress, the DDS design functioning at microcosmic levels is fully challenging and underexploited. Here, we provide an overview describing the recent advances on stimuli-responsive DDSs triggered by intracellular or subcellular microenvironments. Instead of focusing on the targeting strategies as listed in previous reviews, we herein mainly highlight the concept, design, preparation and applications of stimuli-responsive systems in intracellular models. Hopefully, this review could give useful hints in developing nanoplatforms proceeding at a cellular level.

Assessment of synthesized chitosan/halloysite nanocarrier modified by carbon nanotube for pH-sensitive delivery of curcumin to cancerous media

Constructing a system to carry medicine for more effective remedy of cancer has been a leading challenge, as the number of cancer cases continues to increase. In this present research, a curcumin-loaded chitosan/halloysite/carbon nanotube nanomixture was fabricated by means of water/oil/water emulsification method. The drug loading efficiency (DL) and entrapment efficiency (EE), as a result, reached 42 % and 88 %, respectively and FTIR and XRD analysis confirmed the bonding between the drug and nanocarrier. Morphological observation through FE-SEM and characterization through DLS analysis demonstrated that the average size of nanoparticles is 267.37 nm. Assessment of release within 96 h in pH 7.4 and 5.4 showed sustained release. For more investigation, release data was analyzed by diverse kinetic models to understand the mechanism in the release procedure. An MTT assay was also carried out, and the results illustrated apoptosis induction on MCF-7 cells and exhibited ameliorated cytotoxicity of the drug-loaded nanocomposite compared to the free curcumin. These findings suggest that the unique pH-responsive chitosan/halloysite/carbon nanotube nanocomposite might make a good option for drug delivery systems, particularly for the cancer treatment.

Green engineering of TMC-CMS nanoparticles decorated graphene sheets for targeting M. tuberculosis

Our current work intends to primarily engineer a new type of antibacterial composite by preparing a highly biocompatible graphene sheet decorated with TMC-CMS IPNs nanoparticles utilizing one-pot, green, cost-effective ultrasonication approach. The microstructure of as-formed materials was chemically confirmed using various analytical techniques such as ¹H-NMR, FTIR, UV/vis, SEM, and TEM. TEM data has proved the formation of uniformly distributed TCNPs on graphene surfaces with a small particle size of ~22 nm compared with that of pure nanoparticles (~30 nm). The inhibitory activity of these developed materials was examined against the growth of three different M. tuberculosis pathogens and in a comparison with the isoniazid drug as a standard anti-tuberculosis drug. The TCNPs@GRP composite attained MIC values of 0.98, 3.9, and 7.81 μg/mL for inhibiting the growth of sensitive, MDR, and XDR M. tuberculosis pathogens compared to the bare TCNPs (7.81, 31.25, >125 μg/mL) and the isoniazid drug (0.24, 0, 0 μg/mL), respectively. This reveals a considerable synergism in the antituberculosis activity between TCNPs and graphene nanosheets. Cytotoxicity of the TCNPs@GRP was examined against normal lung cell lines (WI38) and was found to have cell viability of 100% with the concentration range of 0.98-7.81 μg/mL.

Nanocarrier design–function relationship: The prodigious role of properties in regulating biocompatibility for drug delivery applications

The concept of drug delivery systems as a magic bullet for the delivery of bioactive compounds has emerged as a promising approach in the treatment of different diseases with significant advantages over the limitations of traditional methods. While nanocarrier-based drug delivery systems are the main advocates of drug uptake because they offer several advantages including reduced non-specific biodistribution, improved accumulation, and enhanced therapeutic efficiency; their safety and biocompatibility within cellular/tissue systems are therefore important for achieving the desired effect. The underlying power of "design-interplay chemistry" in modulating the properties and biocompatibility at the nanoscale level will direct the interaction with their immediate surrounding. Apart from improving the existing nanoparticle physicochemical properties, the balancing of the hosts' blood components interaction holds the prospect of conferring newer functions altogether. So far, this concept has been remarkable in achieving many fascinating feats in addressing many challenges in nanomedicine such as immune responses, inflammation, biospecific targeting and treatment, and so on. This review, therefore, provides a diverse account of the recent advances in the fabrication of biocompatible nano-drug delivery platforms for chemotherapeutic applications, as well as combination therapy, theragnostic, and other diseases that are of interest to scientists in the pharmaceutical industries. Thus, careful consideration of the "property of choice" would be an ideal way to realize specific functions from a set of delivery platforms. Looking ahead, there is an enormous prospect for nanoparticle properties in regulating biocompatibility.

Dual stimuli-responsive cross-linked nanoassemblies from an amphiphilic mannose-6-phosphate based tri-block copolymer for lysosomal membrane permeabilization

Stimuli-responsive cross-linked nanocarriers that can induce lysosomal cell death (LCD) via lysosomal membrane permeabilization (LMP) represent a new class of delivery platforms and have attracted the attention of researchers in the biomedical field. The advantages of such cross-linked nanocarriers are as follows (i) they remain intact during blood circulation; and (ii) they reach the target site via specific receptor-mediated endocytosis leading to the enhancement of therapeutic efficacy and reduction of side effects. Herein, we have synthesized a mannose-6-phosphate (M6P) based amphiphilic ABC type tri-block copolymer having two chains of FDA-approved poly(ε-caprolactone) (PCL) as the hydrophobic block, and poly(S-(o-nitrobenzyl)-L-cysteine) (NBC) acts as the photoresponsive crosslinker block. Two different tri-block copolymers, [(PCL₃₅)₂-b-NBC₂₀-b-^M6PGP₂₀] and [(PCL₃₅)₂-b-NBC₁₅-b-^M6PGP₂₀], were synthesized which upon successful self-assembly initially formed spherical uncross-linked "micellar-type" aggregates (UCL-M) and vesicles (UCL-V), respectively. The uncross-linked nanocarriers upon UV treatment for thirty minutes were covalently crosslinked in the middle PNBC block giving rise to the di-sulfide bonds and forming interface cross-linked "micellar-type" aggregates (ICL-M) and vesicles (ICL-V). DLS, TEM, and AFM techniques were used to successfully characterize the morphology of these nanocarriers. The dual stimuli (redox and enzyme) responsiveness of the cross-linked nanocarriers and their trafficking to the lysosome in mammalian cells via receptor-mediated endocytosis was probed using confocal microscopy images. Furthermore, the addition of a chloroquine (CQ, a known lysosomotropic agent) encapsulated cross-linked nanocarrier (CQ@ICL-V) to non-cancerous (HEK-293T) cells and liver (HepG2), and breast cancer cells (MDA-MB-231) was found to initiate lysosomal membrane permeabilization (LMP) followed by lysosomal destabilization which eventually led to lysosomal cell death (LCD). Due to the targeted delivery of CQ to the lysosomes of cancerous cells, almost a 90% smaller amount of CQ was able to achieve similar cell death to CQ alone.

Hyaluronic Acid-Coated Chitosan Nanoparticles as an Active Targeted Carrier of Alpha Mangostin for Breast Cancer Cells

Alpha mangostin (AM) has potential anticancer properties for breast cancer. This study aims to assess the potential of chitosan nanoparticles coated with hyaluronic acid for the targeted delivery of AM (AM-CS/HA) against MCF-7 breast cancer cells. AM-CS/HA showed a spherical shape with an average diameter of 304 nm, a polydispersity index of 0.3, and a negative charge of 24.43 mV. High encapsulation efficiency (90%) and drug loading (8.5%) were achieved. AM released from AM-CS/HA at an acidic pH of 5.5 was higher than the physiological pH of 7.4 and showed sustained release. The cytotoxic effect of AM-CS/HA (IC₅₀ 4.37 µg/mL) on MCF-7 was significantly higher than AM nanoparticles without HA coating (AM-CS) (IC₅₀ 4.48 µg/mL) and AM (IC₅₀ 5.27 µg/mL). These findings suggest that AM-CS/HA enhances AM cytotoxicity and has potential applications for breast cancer therapy.

Responsive Nanostructure for Targeted Drug Delivery

Currently, intelligent, responsive biomaterials have been widely explored, considering the fact that responsive biomaterials provide controlled and predictable results in various biomedical systems. Responsive nanostructures undergo reversible or irreversible changes in the presence of a stimulus, and that stimuli can be temperature, a magnetic field, ultrasound, pH, humidity, pressure, light, electric field, etc. Different types of stimuli being used in drug delivery shall be explained here. Recent research progress in the design, development and applications of biomaterials comprising responsive nanostructures is also described here. More emphasis will be given on the various nanostructures explored for the smart stimuli responsive drug delivery at the target site such as wound healing, cancer therapy, inflammation, and pain management in order to achieve the improved efficacy and sustainability with the lowest side effects. However, it is still a big challenge to develop well-defined responsive nanostructures with ordered output; thus, challenges faced during the design and development of these nanostructures shall also be included in this article. Clinical perspectives and applicability of the responsive nanostructures in the targeted drug delivery shall be discussed here.

Paclitaxel-loaded tumor cell-derived microparticles improve radiotherapy efficacy in triple-negative breast cancer by enhancing cell killing and stimulating immunity

Triple-negative breast cancer (TNBC) is a highly heterogeneous tumor characterized by high recurrence and metastasis, with a very poor prognosis, and there are still great challenges in its clinical treatment. Here, we describe the development of a novel modality for the treatment of TNBC with tumor cell-derived microparticles loaded with paclitaxel (MP-PTX) in combination with radiotherapy. We show that MP can deliver agents to tumor cells by homologous targeting, thereby increasing the absorption rate of the chemotherapeutic agent and enhancing its killing effects on tumor cells. We further demonstrate that MP-PTX combined with radiotherapy shows a synergistic antitumor effect by enhancing the inhibition of tumor cell proliferation, promoting tumor cell apoptosis, reducing the immunosuppressive microenvironment at the tumor site, and activating the antitumor immune response. Altogether, this study provides a referable and optional method for the clinical treatment of refractory tumors such as TNBC based on the combination of T-MP-delivered chemotherapeutic drugs and radiotherapy. Chemical compounds: paclitaxel (PTX), paclitaxel-loaded tumor cell-derived microparticles (MP-PTX).