Nanoassemblies designed for efficient nuclear targeting

One of the key aspects of coping efficiently with complex pathological conditions is delivering the desired therapeutic compounds with precision in both space and time. Therefore, the focus on nuclear-targeted delivery systems has emerged as a promising strategy with high potential, particularly in gene therapy and cancer treatment. Here, we explore the design of supramolecular nanoassemblies as vehicles to deliver specific compounds to the nucleus, with the special focus on polymer and peptide-based carriers that expose nuclear localization signals. Such nanoassemblies aim at maximizing the concentration of genetic and therapeutic agents within the nucleus, thereby optimizing treatment outcomes while minimizing off-target effects. A complex scenario of conditions, including cellular uptake, endosomal escape, and nuclear translocation, requires fine tuning of the nanocarriers' properties. First, we introduce the principles of nuclear import and the role of nuclear pore complexes that reveal strategies for targeting nanosystems to the nucleus. Then, we provide an overview of cargoes that rely on nuclear localization for optimal activity as their integrity and accumulation are crucial parameters to consider when designing a suitable delivery system. Considering that they are in their early stages of research, we present various cargo-loaded peptide- and polymer nanoassemblies that promote nuclear targeting, emphasizing their potential to enhance therapeutic response. Finally, we briefly discuss further advancements for more precise and effective nuclear delivery.

Mediation of synergistic chemotherapy and gene therapy via nanoparticles based on chitosan and ionic polysaccharides

Nanoparticles (NPs)-based on various ionic polysaccharides, including chitosan, hyaluronic acid, and alginate have been frequently summarized for controlled release applications, however, most of the published reviews, to our knowledge, focused on the delivery of a single therapeutic agent. A comprehensive summarization of the co-delivery of multiple therapeutic agents by the ionic polysaccharides-based NPs, especially on the optimization of the polysaccharide structure for overcoming various extracellular and intracellular barriers toward maximized synergistic effects, to our knowledge, has been rarely explored so far. For this purpose, the strategies used for overcoming various extracellular and intracellular barriers in vivo were introduced first to provide guidance for the rational design of ionic polysaccharides-based NPs with desired features, including long-term circulation, enhanced cellular internalization, controllable drug/gene release, endosomal escape and improved nucleus localization. Next, four preparation strategies were summarized including three physical methods of polyelectrolyte complexation, ionic crosslinking, and self-assembly and a chemical conjugation approach. The challenges and future trends of this rapidly developing field were finally discussed in the concluding remarks. The important guidelines on the rational design of ionic polysaccharides-based NPs for maximized synergistic efficiency drawn in this review will promote the future generation and clinical translation of polysaccharides-based NPs for cancer therapy.

The Apoptosis of Liver Cancer Cells Promoted by Curcumin/TPP-CZL Nanomicelles With Mitochondrial Targeting Function

The mitochondrion is one of the most important cellular organelles, and many drugs work by acting on mitochondria. Curcumin (Cur)-induced apoptosis of HepG2 in liver cancer cells is closely related to the function of inhibiting mitochondria. However, the mitochondrion-targeting curcumin delivery system was rarely been reported. It is important to develop a high-efficiency mitochondrion-targeting curcumin vector that can deliver curcumin into mitochondria directly. Here, a special mitochondrion-targeting delivery system based on triphenylphosphine bromide (TPP)-chitosan-g-poly-(N-3-carbobenzyloxy-l-lysine) (CZL) with TPP functional on the surface is designed to perform highly efficient mitochondria-targeting delivery for effective liver cancer cell killing in vitro. The TEM images showed that the nanomicelles were spherical; the results of fluorescence test showed that TPP-CZL nanomicelles could promote the cellular uptake of drugs and finally targeted to the mitochondria. The results of cell survival rate and Hoechst staining showed that curcumin/TPP-CZL nanomicelles could promote the apoptosis of liver cancer cells. Curcumin/TPP-CZL nanomicelles could significantly reduce the mitochondrial membrane potential, increase the expression of pro apoptotic protein Bcl-2, and reduce the expression of antiapoptotic Bax protein, and these results were significantly better than curcumin/CZL nanomicelles and curcumin. It is a potential drug delivery system with high efficiency to target mitochondria of liver cancer cells.

The Anti-Inflammation and Anti-Nociception Effect of Ketoprofen in Rats Could Be Strengthened Through Co-Delivery of a H2S Donor, S-Propargyl-Cysteine

PURPOSE

Ketoprofen (KETO) is a traditional non-steroidal anti-inflammatory drug (NSAIDs) with good analgesic and antipyretic effects. However, as NASIDs, the toxicity of KETO towards gastrointestinal (GI) system might limit its clinical use. S-propargyl-cysteine (SPRC) is an excellent endogenous H2S donor showed wide application in the field of anti-inflammation, anti-oxidative stress, or even the protection of cardiovascular system through the elevation of endogenous H2S concentration. As recently studies reported, co-administration of H2S donor might potentially mitigate the GI toxicity and relevant side effects induced by series of NSAIDs.

METHODS

In this study, we established a SPRC and KETO co-encapsulated poly (lactic-co-glycolic acid) microsphere (SK@MS), and its particle size, morphology, storage stability and in vitro release profile were firstly investigated. The elevation of endogenous H2S level of SK@MS was then calculated, and the pharmacodynamic study (anti-inflammation and analgesic effects) of SK@MS, SPRC, and KETO towards adjuvant induced arthritis (AIA) in rats were also studied. Finally, to test the potential side effect, the heart, liver, spleen, lung, kidney, stomach, small intestine, and large intestine were resected from rats and examined by H&E staining.

RESULTS

A monodispersed SK@MS could be observed under the SEM, and particle size was calculated around 25.12 μm. The loading efficiency (LE) for SPRC and KETO were 6.67% and 2.64%, respectively, while the encapsulation efficiency (EE) for SPRC and KETO were 37.20% and 68.28%, respectively. SK@MS showed a sustained release of SPRC and KETO in vitro, which was up-to 15 days. SK@MS could achieve a long-term elevation of the H2S concentration in vivo, while SPRC showed an instant H2S elevation and metabolize within 6 h. Interestingly, the KETO did not show any influence on the H2S concentration in vivo. After establishment of AIA model, neither SPRC nor KETO showed scarcely anti-inflammation and anti-nociception effect, while conversely, SK@MS showed an obvious mitigation towards paw edema and pain in AIA rats, which indicated an improved anti-inflammation and anti-nociception effect when co-delivery of SRC and KETO. Besides, low stimulation towards major organs in rats observed in any experimental group.

CONCLUSION

A monodispersed was successfully prepared in this study, and SK@MS showed a sustained SPRC and KETO release in vitro and H2S release in vivo. In the pharmacodynamics study, SK@MS not only exhibited an excellent anti-inflammation and analgesic effects in AIA rats but also showed low stimulation towards rats.

Poly(α-l-lysine)-based nanomaterials for versatile biomedical applications: Current advances and perspectives

Poly(α-l-lysine) (PLL) is a class of water-soluble, cationic biopolymer composed of α-l-lysine structural units. The previous decade witnessed tremendous progress in the synthesis and biomedical applications of PLL and its composites. PLL-based polymers and copolymers, till date, have been extensively explored in the contexts such as antibacterial agents, gene/drug/protein delivery systems, bio-sensing, bio-imaging, and tissue engineering. This review aims to summarize the recent advances in PLL-based nanomaterials in these biomedical fields over the last decade. The review first describes the synthesis of PLL and its derivatives, followed by the main text of their recent biomedical applications and translational studies. Finally, the challenges and perspectives of PLL-based nanomaterials in biomedical fields are addressed.

Recent advances in peptide-targeted micelleplexes: Current developments and future perspectives

The decoding of the human genome revolutionized the understanding of how genetics influence the interplay between health and disease, in a multidisciplinary perspective. Thus, the development of exogenous nucleic acids-based therapies has increased to overcome hereditary or acquired genetic-associated diseases. Gene drug delivery using non-viral systems, for instance micelleplexes, have been recognized as promising options for gene-target therapies. Micelleplexes are core-shell structures, at a nanometric scale, designed using amphiphilic block copolymers. These can self-assemble in an aqueous medium, leading to the formation of a hydrophilic and positively charged corona - that can transport nucleic acids, - and a hydrophobic core - which can transport poor water-soluble drugs. However, the performance of these types of carriers usually is hindered by several in vivo barriers. Fortunately, due to a significant amount of research, strategies to overcome these shortcomings emerged. With a wide range of structural features, good stability against proteolytic degradation, affordable characteristic, easy synthesis, low immunogenicity, among other advantages, peptides have increasingly gained popularity as target ligands for non-viral carriers. Hence, this review addresses the use of peptides with micelleplexes illustrating, through the analysis of in vitro and in vivo studies, the potential and future perspectives of this combination.

New Water-Soluble Oxyamino Chitosans as Biocompatible Vectors for Efficacious Anticancer Therapy via Co-Delivery of Gene and Drug

Among the many nonviral gene delivery vectors, chitosan, being a polysaccharide of natural origin, has gained special importance. In this report, chitosan (CS) has been solubilized in water by preparing its O-carboxymethyl derivative, CS(CH₂COOH), with an optimum degree of carboxymethylation. This has been further derivatized to get the pyridine-substituted product (py)CS(CH₂COOH), where the degree of pyridine substitution (47%) was optimized based on zeta potential measurements. The optimized formulation showed a high gene binding ability, forming nanosized positively charged polyelectrolyte complexes with DNA. These polyplexes were stable to DNase and physiological polyanions such as heparin. They also exhibited minimal toxicity in vitro and showed transfection levels comparable to the commercial standard Lipofectamine 2000 and much higher than polyethylenimine (MW, 25 kDa). Additionally, in this study, a hitherto unknown oxyamine derivative of chitosan has been prepared by phthaloyl protection, tosylation, and Gabriel's phthalimide synthesis. Nearly 40% of the primary alcohols were successfully converted to oxyamino functionality, which was used for forming oxime with the anticancer drug doxorubicin. The pH sensitivity of the oxime ether linkage and stability under biologically relevant conditions were then used to establish the compound as a versatile drug delivery vector. Co-delivery of functional gene (p53) and drug (doxorubicin) was accomplished in vitro and in vivo with the chitosan-pyridine imine vector (py)CS(CH₂COOH) and the newly synthesized doxorubicin oxime ether CS(Dox). Complete tumor regression with no tumor recurrence and appreciable survivability point to the in vivo effectiveness and biocompatibility of the designed composite formulation. Overall, the pH sensitivity of the oxime linkage aiding slow and steady drug release, together with the sustained gene expression by pyridine-tethered carboxymethyl chitosan, allows us to generate a nanobiocomposite with significantly high anticancer therapeutic potential.

Nuclear-targeted p53 and DOX co-delivery of chitosan derivatives for cancer therapy in vitro and in vivo

The nucleus is one of the most important cellular organelles. Chitosan-grafted poly-(N-3-carbobenzyloxy-lysine) (CCL) decorated with human immunodeficiency virus-1 transactivator of transcription (TAT) can co-deliver p53 and doxorubicin into the nucleus simultaneously, such that their antitumor functions are exerted. However, TAT-CCL has been shown to have an anti-tumor effect only in vitro; the effect in vivo was unsatisfactory. Here, a unique nucleus-targeted delivery system based on amidized TAT (aTAT)-CCL with aTAT functional on the surface was designed to achieve a highly efficient nucleus-targeting gene and drug delivery system for effective cancer cell elimination in vitro and in vivo. In this delivery system, TAT is amidized to inhibit its nonspecific interactions. Confocal laser scanning microscopy observations revealed that if aTAT-CCL was incubated in pH 5.0 acetate buffer solution for 24 h before use (named aTAT-CCL-HB), more aTAT-CCL-HB entered the nucleus compared with aTAT-CCL or CCL. aTAT-CCL-HB can also achieve high gene transfection and drug delivery efficiencies and low viability in HepG2 cells. However, only aTAT-CCL achieved extensive circulation in the blood compartment and high antitumor activity in vivo. Amidization of TAT in vectors may become a promising strategy for nucleus-targeted delivery systems, especially in in vivo applications.

TAT-conjugated chitosan cationic micelle for nuclear-targeted drug and gene co-delivery

We developed a high-efficiency nucleus-targeted co-delivery vector that delivers genes and drugs directly into the nucleus of cancer cells. The system is based on grafted poly-(N-3-carbobenzyloxy-lysine) (CPCL) with transactivator of transcription (TAT)- chitosan on the surface. It is designed to perform highly efficient nucleus- targeted gene and drug co-delivery. Confocal laser scanning microscopy (CLSM) revealed that more TAT-CPCL entered the nucleus than does CPCL alone. The TAT-modified vector serves as a gene and drug co-delivery mechanism to achieve high gene transfection efficiency, high apoptosis and low viability in HeLa cells. TAT-CPCL may become a vector for cancer gene treatment and a template for designing better co-deliver systems.

ATP triggered drug release and DNA co-delivery systems based on ATP responsive aptamers and polyethylenimine complexes

Stimuli-responsive nanocarriers for anticancer drug and gene co-delivery are a promising strategy in cancer therapy due to their combination of chemotherapy and gene therapy. In this work, we developed a facile and effective method to fabricate stimuli-responsive nanocarriers for anticancer drug and gene co-delivery based on complexes of polyethylenimine (PEI) with an adenosine triphosphate (ATP) responsive aptamer duplex (ARAD). No chemical reactions or complex modifications were used in the construction processes. In this system, Doxorubicin-loaded aptamer duplex and plasmid DNA (p53) can be bound by PEI by electronic interactions to form stable complexes which effectively protect the aptamer and p53 from DNase degradation. The intercalated Dox can be released on-demand by a structural change in the aptamer duplex in an ATP-rich environment. The morphology and average size of the nanocarriers were characterized by zeta potential and transmission electron microscopy (TEM). The nanocarriers exhibit lower cell toxicity in HeLa cell lines relative to PEI. RT-PCR and Western blot analysis confirmed that p53 could be effectively delivered and expressed in HeLa cells by PEI/ARAD/p53 complexes. Moreover, the apoptosis percentage of HeLa cells treated with PEI/ARAD/Dox/p53 complex increased to 40.8%, compared to 24.7% for PEI/ARAD/Dox complex and 11.5% for PEI/ARAD/p53, respectively. The result demonstrated that the combinatorial delivery of Dox and p53 by nanocarriers could induce synergistic actions and lead to effective cancer cell apoptosis.

Reduction-sensitive amphiphilic dextran derivatives as theranostic nanocarriers for chemotherapy and MR imaging

Reduction-sensitive, amphiphilic dextran derivatives were developed from disulfide-linked dextran-g-poly-(N-ε-carbobenzyloxy-l-lysine) graft polymer (Dex-g-SS-PZLL), and used as theranostic nanocarriers for chemotherapy and MR imaging.