Macroporous silica nanoparticles for delivering Bcl2-function converting peptide to treat multidrug resistant-cancer cells

pH-responsive Aminated mesoporous silica microspheres modified with soybean hull polysaccharides for curcumin encapsulation and controlled release

Mesoporous silica microspheres (MSMs) possess poor biocompatibility. This study focuses on integrating MSMs with polymers to obtain hybrid materials with superior performance compared to the individual components and responsive release in specific environments. The synthesized MSMs were aminated, and subsequently, soybean hull polysaccharide (SHPs) was modified onto MSMs-NH2 to produce MSMs-NH2@SHPs nanoparticles. The encapsulation rate, loading rate of curcumin (Cur), and in vitro release behavior were investigated. Results indicated that the encapsulation efficiency of Cur by MSMs-NH2@SHPs nanoparticles reached 75.58%, 6.95 times that of MSMs-NH2 with a load capacity of 35.12%. It is noteworthy that these nanoparticles exhibit pH-responsive release capacity in vitro. The cumulative release rate of the three nanoparticles at pH 5.0 was higher than that at pH 7.4. MSMs-NH2@SHPs had a cumulative release rate of 56.55% at pH 7.4, increasing to 76.21% at pH 5.0. In vitro experiments have shown that MSMs-based nanoparticles have high delivery efficiency and can achieve pH-sensitive drug release, with a high release rate in a slightly acidic acid, highlighting the potential for controlled release of Cur.

Unlocking nature's arsenal: Nanotechnology for targeted delivery of venom toxins in cancer therapy

AIM

The aim of the present review is to shed light on the nanotechnological approaches adopted to overcome the shortcomings associated with the delivery of venom peptides which possess inherent anti-cancer properties.

BACKGROUND

Venom peptides although have been reported to demonstrate anti-cancer effects, they suffer from several disadvantages such as in vivo instability, off-target adverse effects, limited drug loading and low bioavailability. This review presents a comprehensive compilation of different classes of nanocarriers while underscoring their advantages, disadvantages and potential to carry such peptide molecules for in vivo delivery. It also discusses various nanotechnological aspects such as methods of fabrication, analytical tools to assess these nanoparticulate formulations, modulation of nanocarrier polymer properties to enhance loading capacity, stability and improve their suitability to carry toxic peptide drugs.

CONCLUSION

Nanotechnological approaches bear great potential in delivering venom peptide-based molecules as anticancer agents by enhancing their bioavailability, stability, efficacy as well as offering a spatiotemporal delivery approach. However, the challenges associated with toxicity and biocompatibility of nanocarriers must be duly addressed.

PERSPECTIVES

The everlasting quest for new breakthroughs for safer delivery of venom peptides in human subjects is fuelled by unmet clinical needs in the current landscape of chemotherapy. In addition, exhaustive efforts are required in obtaining and purifying the venom peptides followed by designing and optimizing scale up technologies.

Acid-Responsive Macroporous Silica Nanoparticles for Bcl-2-Functional-Converting Peptide Release and Synergism with Celastrol for Enhanced Therapy against Resistant Cancer

Combination of chemotherapeutics with polypeptide/protein drugs has been demonstrated to be an effective approach for treatment against cancer multidrug resistance. However, due to the low biostability and weak cell penetrating ability of biomacromolecules, intracellular delivery and release of biomacromolecules in a spatiotemporally controllable manner in target sites in vivo face great challenges, and synergistic effects will not be achieved as expected just by simple drug combination. Here, we conceived an inspired strategy to combat the drug-resistant tumors by fabricating multiarm PEG-gated large pore-sized mesoporous silica nanoparticles for the Bcl-2-functional-converting peptide (denoted as N9@M-CA∼8P) payload and controlled release and realizing synergistic effects with celastrol integration at a low dosage as a curative sensitizer. Our results demonstrated that the N9 peptide could be pH-responsively released from the macropores of the M-CA∼8P nanosystem both in simulated physiological environments and in cancer cells and at tumor sites. Biosafe and enhanced therapeutic outcomes (90% tumor inhibition) were obtained by combination of the N9@M-CA∼8P nanosystem with celastrol coordinatively inducing mitochondrion-mediated cell apoptosis in resistant cancer cell lines and in the corresponding xenografted mice models. Overall, this study provides convincing evidence for effective and safe resistant cancer treatment through a stimulus-responsive biomacromolecule nanosystem combined with a low dosage of a natural compound.

Enhanced Protein Adsorption Capacity of Macroporous Pectin Particles with High Specific Surface Area and an Interconnected Pore Network

There has been much interest in developing protein adsorbents using nanostructured particles, which can be engineered porous materials with fine control of the surface and pore structures. A significant challenge in designing porous adsorbents is the high percentage of available binding sites in the pores owing to their large surface areas and interconnected pore networks. In this study, continuing the idea of using porous materials derived from natural polymers toward the goal of sustainable development, porous pectin particles are reported. The template-assisted spray drying method using calcium carbonate (CaCO₃) as a template for pore formation was applied to prepare porous pectin particles. The specific surface area was controlled from 177.0 to 222.3 m² g^-1 by adjusting the CaCO₃ concentration. In addition, the effects of a macroporous structure, the specific surface area, and an interconnected pore network on the protein (lysozyme) adsorption capacity and adsorption mechanism were investigated. All porous pectin particles performed rapid adsorption (∼65% total capacity within 5 min) and high adsorption capacity, increasing from 1543 to the highest value of 2621 mg g^-1. The results are attributed to the high percentage of available binding sites located in the macropores owing to their large surface areas and interconnected pore networks. The macroporous particles obtained in this study showed a higher adsorption capacity (2621 mg g^-1) for lysozyme than other adsorbents. Moreover, the rapid uptake and high performance of this material show its potential as an advanced adsorbent for various macromolecules in the food and pharmaceutical fields.

Understanding the interactions between inorganic-based nanomaterials and biological membranes

The interactions between inorganic-based nanomaterials (NMs) and biological membranes are among the most important phenomena for developing NM-based therapeutics and resolving nanotoxicology. Herein, we introduce the structural and functional effects of inorganic-based NMs on biological membranes, mainly the plasma membrane and the endomembrane system, with an emphasis on the interface, which involves highly complex networks between NMs and biomolecules (such as membrane proteins and lipids). Significant efforts have been devoted to categorizing and analyzing the interaction mechanisms in terms of the physicochemical characteristics and biological effects of NMs, which can directly or indirectly influence the effects of NMs on membranes. Importantly, we summarize that the biological membranes act as platforms and thereby mediate NMs-immune system contacts. In this overview, the existing challenges and potential applications in the areas are addressed. A strong understanding of the discussed concepts will promote therapeutic NM designs for drug delivery systems by leveraging the NMs-membrane interactions and their functions.

Impact of macroporous silica nanoparticles at sub-50nm on bio-behaviors and biosafety in drug-resistant cancer models

The in vivo bio-behaviors and biosafety of nanoparticles were demonstrated to be closely correlated with particle sizes, which illustrated whether they could be used as the effective drug delivery carriers. Though tumor penetration capabilities of the small pore sized-mesoporous silica nanoparticles (MSNs) were reported to be in a particle size-dependent manner, the size effects of large pore sized-MSNs on the safe and effective cancer resistance treatment, especially at sub-50 nm, were not explicitly evaluated. In this study, we fabricate the 20 nm and 50 nm MSNs, and aim at investigating their difference in tumor accumulation, penetration, retention and toxicity both in vitro and in vivo. Our results showed that these two particle sized-MSNs possessed the excellent tumor penetration capabilities both in resistant human hepatocellular carcinoma cells-cultured spheroids and in the corresponding xenograft mice models, but the 50 nm MSNs seemed to have the better tumor accumulation and retention effects than the 20 nm MSNs. Moreover, the 50 nm MSNs displayed the lower toxicities than the 20 nm MSNs whatever on resistant cancer cell lines or on zebrafish embryos, indicating the greater systematic biosafety. In a word, our data provide the evidence that selection of the large pore-sized MSNs at the appropriate particle size (not the smaller the better) as bio-macromolecule nanocarriers will play a key role in the safe and effective treatment against cancer resistance.

Combination of mitochondria targeting doxorubicin with Bcl-2 function-converting peptide NuBCP-9 for synergistic breast cancer metastasis inhibition

Distant organ metastasis is the main cause of death in breast cancer patients. Evidences have shown that mitochondria also play a crucial role in tumor metastasis, except for as apoptosis center. However, the treatment of tumor growth and metastasis was reported to be limited by mitochondria-associated protein Bcl-2, which are gatekeepers of apoptosis and are found to reside in mitochondria mainly. Herein, we designed a mitochondria-targeting doxorubicin delivery system as well as a mitochondrial distributed Bcl-2 function-converting peptide NuBCP-9 delivery system, which are both based on N-(2-hydroxypropyl)methacrylamide copolymers, to achieve a synergistic effect on tumor regression and metastasis inhibition by combination therapy. After mitochondria were damaged by mitochondria-targeting peptide-modified doxorubicin, apoptosis was effectively enhanced by mitochondrial specifically distributed NuBCP-9 peptides, which converted Bcl-2 function from anti-apoptotic to pro-apoptotic and paved the way for the development of mitochondrial impairment. The combination treatment exhibited significant damage to mitochondria, including excess reactive oxygen species (ROS), the permeabilization of mitochondrial outer membrane (MOMP), and apoptosis initiation on 4T1 breast cancer cells. Meanwhile, besides enhanced tumor growth suppression, the combination treatment also improved the inhibition of 4T1 breast cancer metastasis both in vitro and in vivo. By increasing the expression of cytochrome C and decreasing the expression of Bcl-2, metal matrix protease-9 (MMP-9) as well as vascular endothelial growth factor (VEGF), the combination treatment successfully decreased 84% lung metastasis. Overall, our work provided a promising strategy for metastatic cancer treatment through mitochondria-targeting anti-cancer drug delivery and combination with mitochondrial distributed Bcl-2 function-converting peptide.

Mesoporous Silica Nanoparticles as Carriers for Biomolecules in Cancer Therapy

Mesoporous silica nanoparticles (MSNs) offer many advantageous properties for applications in the field of nanobiotechnology. Loading of small molecules into MSNs is straightforward and widely applied, but with the upswing of both research and commercial interest in biological drugs in recent years, also biomacromolecules have been loaded into MSNs for delivery purposes. MSNs possess many critical properties making them a promising and versatile carrier for biomacromolecular delivery. In this chapter, we review the effects of the various structural parameters of MSNs on the effective loading of biomacromolecular therapeutics, with focus on maintaining stability and drug delivery performance. We also emphasize recent studies involving the use of MSNs in the delivery of biomacromolecular drugs, especially for cancer treatment.

Macroporous organosilicon nanocomposites co-deliver Bcl2-converting peptide and chemotherapeutic agent for synergistic treatment against multidrug resistant cancer

Therapeutic biomacromolecules are confronted with in vivo challenges of low bio-stability and poor tumor tissue-penetration. Herein, we report for the first time, our development and characterization of a hybrid nanocomposite for delivering a Bcl-2-converting peptide (NuBCP9, N9 hereafter) and testing its efficacy alone or together with doxorubicin (DOX). The hybrid nanocomposite is composed of the internal large pore sized-mesoporous silica nanoparticles (MSNs) and the external highly-branched polyamidoamine (PAMAM) dendrimers, into which N9 peptide and DOX were encapsulated for the different sub-cellular delivery to treat drug-resistant cancer. The nanocomposite possessed the particle and pore sizes of ~37 nm and ~8 nm, which displayed the superior tumor penetration capacity over naked MSNs both in cultured-3D tumor sphere and in live animal models. Moreover, the dual drug nanocomposite exhibited a great synergistic anticancer effect on Bcl-2-positive cancer cells in vitro and animals with the negligible toxic side effects. The tumor inhibition rate of the nanocomposite (89%) was five times as much as the two drugs combination. This design provides a new effective, safe and versatile strategy to fabricate large pore-sized MSNs with the organic-inorganic hybrid framework to concurrently transport therapeutic peptides and chemotherapeutics to the specific sub-cellular locations for the synergistic cancer therapy and drug resistance reversal, which has significant impact on the development of improved cancer therapeutics.

Current trends and challenges in cancer management and therapy using designer nanomaterials

Nanotechnology has the potential to circumvent several drawbacks of conventional therapeutic formulations. In fact, significant strides have been made towards the application of engineered nanomaterials for the treatment of cancer with high specificity, sensitivity and efficacy. Tailor-made nanomaterials functionalized with specific ligands can target cancer cells in a predictable manner and deliver encapsulated payloads effectively. Moreover, nanomaterials can also be designed for increased drug loading, improved half-life in the body, controlled release, and selective distribution by modifying their composition, size, morphology, and surface chemistry. To date, polymeric nanomaterials, metallic nanoparticles, carbon-based materials, liposomes, and dendrimers have been developed as smart drug delivery systems for cancer treatment, demonstrating enhanced pharmacokinetic and pharmacodynamic profiles over conventional formulations due to their nanoscale size and unique physicochemical characteristics. The data present in the literature suggest that nanotechnology will provide next-generation platforms for cancer management and anticancer therapy. Therefore, in this critical review, we summarize a range of nanomaterials which are currently being employed for anticancer therapies and discuss the fundamental role of their physicochemical properties in cancer management. We further elaborate on the topical progress made to date toward nanomaterial engineering for cancer therapy, including current strategies for drug targeting and release for efficient cancer administration. We also discuss issues of nanotoxicity, which is an often-neglected feature of nanotechnology. Finally, we attempt to summarize the current challenges in nanotherapeutics and provide an outlook on the future of this important field.