Characterization and bioactivity of self-assembled anti-angiogenic chondroitin sulfate-ES2-AF nanoparticle conjugate

Chondroitin sulfate-based universal nanoparticle delivers angiogenic inhibitor and paclitaxel to exhibit a combination of chemotherapy and anti-angiogenic therapy

Blocking the tumor nutrient supply through angiogenic inhibitors is an effective treatment approach for malignant tumors. However, using angiogenic inhibitors alone may not be enough to achieve a significant tumor response. Therefore, we recently designed a universal drug delivery system combining chemotherapy and anti-angiogenic therapy to target tumor cells while minimizing drug-related side effects. This system (termed as PCCE) is composed of biomaterial chondroitin sulfate (CS), the anti-angiogenic peptide ES2, and paclitaxel (PTX), which collectively enhance antitumor properties. Interestingly, the PCCE system is conferred exceptional cell membrane permeability due to inherent characteristics of CS, including CD44 receptor-mediated endocytosis. The PCCE could respond to the acidic and high glutathione conditions, thereby releasing PTX and ES2. PCCE could effectively inhibit the proliferation, migration, and invasion of tumor cells and cause apoptosis, while PCCE can affect the endothelial cells tube formation and exert anti-angiogenic function. Consistently, more potent in vivo antitumor efficacy and non-toxic sides were demonstrated in B16F10 xenograft mouse models. PCCE can achieve excellent antitumor activity via modulating angiogenic and apoptosis-related factors. In summary, we have successfully developed an intelligent and responsive CS-based nanocarrier known as PCCE for delivering various antitumor drugs, offering a promising strategy for treating malignant tumors.

Chondroitin sulfate-modified antiangiogenic peptide conjugate induces cell apoptosis via the mitochondria-mediated pathway to perform antitumor activity

Tumor growth and metastasis heavily rely on angiogenesis, crucial for solid tumor development. Inhibiting angiogenesis associated with tumors emerges as a potent therapeutic approach. Our previous work synthesized the chondroitin sulfate-modified antiangiogenic peptide CS-ES2-AF (CS-EA), which exhibited better antiangiogenic activity, longer half-life, and more robust targeting. In this work, we further evaluated the stability in vitro, cellular uptake mechanism, cell apoptosis mechanism, antitumor activity in vivo, and safety of CS-EA. The stability of CS-EA was consistently superior to that of EA at different temperatures and in different pH ranges. Furthermore, CS-EA mainly entered EAhy926 cells through the clathrin-mediated endocytosis pathway. CS-EA inhibited endothelial cell proliferation, and induced cell apoptosis through downregulating the Bcl-2, reducing mitochondria membrane potential, upregulating cytochrome c, Caspase 3, and reactive oxygen species levels. CS-EA showed better antitumor activity in the B16 xenografted tumor model, with a tumor inhibition rate 1.92 times higher than EA. Simultaneously, it was observed that CS-EA did not cause any harmful effects on the vital organs of the mice. These findings indicate that CS-EA holds significant promise for the treatment of tumors.

Emerging applications of anti-angiogenic nanomaterials in oncotherapy

Angiogenesis is the process of generating new blood vessels from pre-existing vasculature. Under normal conditions, this process is delicately controlled by pro-angiogenic and anti-angiogenic factors. Tumor cells can produce plentiful pro-angiogenic molecules promoting pathological angiogenesis for uncontrollable growth. Therefore, anti-angiogenic therapy, which aims to inhibit tumor angiogenesis, has become an attractive approach for oncotherapy. However, classic anti-angiogenic agents have several limitations in clinical use, such as lack of specific targeting, low bioavailability, and poor therapeutic outcomes. Hence, alternative angiogenic inhibitors are highly desired. With the emergence of nanotechnology, various nanomaterials have been designed for anti-angiogenesis purposes, offering promising features like excellent targeting capabilities, reduced side effects, and enhanced therapeutic efficacy. In this review, we describe tumor vascular features, discuss current dilemma of traditional anti-angiogenic medicines in oncotherapy, and underline the potential of nanomaterials in tumor anti-angiogenic therapy. Moreover, we discuss the current challenges of anti-angiogenic cancer treatment. We expect that this summary of anti-angiogenic nanomaterials in oncotherapy will offer valuable insights, facilitating their extensive applications in the future.

CD44 targeting nanodrug based on chondroitin sulfate for melanoma therapy by inducing mitochondrial apoptosis pathways

Neovascularization is crucial to the occurrence and progression of tumors, and the development of antiangiogenic drugs has essential theoretical value and clinical significance. However, antiangiogenesis therapy alone cannot meet the needs of tumor therapy. Meanwhile, polysaccharides are ideal drug carriers with promising applications in drug modification and delivery. In this research, we developed a novel redox and acid sensitive nanodrug (CDDP-CS-Cys-EA, CCEA) composed of chondroitin sulfate (CS), antiangiogenic peptide (endostatin2-alft1, EA) and chemotherapeutic drug (cisplatin, CDDP). CCEA exhibited redox and acid responsiveness, better blood hemocompatibility (hemolysis rate < 5 %), the ability to target tumors (CD44-mediated endocytosis), and strong antiangiogenesis and antitumor characteristics in vitro. Moreover, CCEA showed excellent antitumor activity and low toxicity in B16 xenograft mice. It also has been confirmed that CCEA induced tumor cell apoptosis through promoting the expression of Bax, suppressing the expression of Bcl-2, decreasing mitochondrial membrane potential, releasing cytochrome C (Cyto C), and enhancing the activities of Caspase 9 and Caspase 3. The results of this paper provided a theoretical basis and insight for the development of antitumor drugs.

Biotechnological advances in the synthesis of modified chondroitin towards novel biomedical applications

Chondroitin sulfate (CS) is a well-known glycosaminoglycan present in a large variety of animal tissues, with an outstanding structural heterogeneity mainly related to molecular weight and sulfation pattern. Recently, few microorganisms, eventually engineered, proved able to synthesize the CS biopolymer backbone, composed of d-glucuronic acid and N-acetyl-d-galactosamine linked through alternating β-(1-3)- and β-(1-4)-glycosidic bonds, and secrete the biopolymers generally unsulfated and possibly decorated with other carbohydrates/molecules. Enzyme catalyzed/assisted methods and chemical tailored protocols allowed to obtain a variety of macromolecules not only resembling the natural extractive ones, but even enlarging the access to unnatural structural features. These macromolecules have been investigated for their bioactivity in vitro and in vivo establishing their potentialities in an array of novel applications in the biomedical field. This review aims to present an overview of the advancements in: i) the metabolic engineering strategies and the biotechnological processes towards chondroitin manufacturing; ii) the chemical approaches applied to obtain specific structural features and targeted decoration of the chondroitin backbone; iii) the biochemical and biological properties of the diverse biotechnological-sourced chondroitin polysaccharides reported so far, unraveling novel fields of applications.

Glycol-Split Heparin-Linked Prodrug Nanoparticles Target the Mitochondrion Apparatus for Cancer Metastasis Treatment

The progression and metastasis of solid tumors rely strongly on neovascularization. However, angiogenesis inhibitors alone cannot meet the needs of tumor therapy. This study prepared a new drug conjugate (PTX-GSHP-CYS-ES2, PGCE) by combining polysaccharides (heparin without anticoagulant activity, GSHP), chemotherapeutic drugs (paclitaxel, PTX), and antiangiogenic drugs (ES2). Furthermore, a tumor-targeted prodrug nanoparticle delivery system is established. The nanoparticles appear to accumulate in the mitochondrial of tumor cells and achieve ES2 and PTX release under high glutathione and acidic environment. It has been confirmed that PGCE inhibited the expression of multiple metastasis-related proteins by targeting the tumor cell mitochondrial apparatus and disrupting their structure. Furthermore, PGCE nanoparticles inhibit migration, invasion, and angiogenesis in B16F10 tumor-bearing mice and suppress tumor growth and metastasis in vitro. Further in vitro and in vivo experiments show that PGCE has strong antitumor growth and metastatic effects and exhibits efficient anti-angiogenesis properties. This multi-targeted nanoparticle system potentially enhances the antitumor and anti-metastatic effects of combination chemotherapy and antiangiogenic drugs.

Plasma metabolites-based design of long-acting peptides and their anticancer evaluation

Antimicrobial peptides (AMPs) are generally small cationic amphipathic peptides, which are thought to be ideal antineoplastic agents, owing to their favorable selectivity to cancer cells and the ability to overcome drug-resistance. In this study, an anticancer AMP (Mastoparan (INLKALAALAKKIL-NH2)) was selected as the lead compound and a series of Mastoparan derivatives were designed. Preliminary studies verified that an analogue of Mastoparan, KM8 (KLLKINLKALAALAKKIL-NH2), exhibited prominent selective antitumor effects. Instead, it presents a significant defect of metabolic instability, with a half-life in plasma of only about 0.5 h. Metabolite profiling of KM8 was performed and indicated the structure ₉AL₁₀ in peptide sequence could be the fragile site for KM8. Thus, the Aib (unnatural amnio acid) was employed to substitute the ₉Ala residue in KM8, and generating a long-acting KM8 derivative, namely KM8-Aib. Further investigations revealed KM8-Aib possessed higher metabolic stability, more potent anticancer activity in vitro & in vivo, and lower toxicity. Therefore, KM8-Aib is suggested be a potential antimalignant agent that worthy of more in-depth study.

Chondroitin sulfate-based composites: a tour d'horizon of their biomedical applications

Chondroitin sulfate (CS), a natural anionic mucopolysaccharide, belonging to the glycosaminoglycan family, acts as the primary element of the extracellular matrix (ECM) of diverse organisms. It comprises repeating units of disaccharides possessing β-1,3-linked N-acetyl galactosamine (GalNAc), and β-1,4-linked D-glucuronic acid (GlcA), and exhibits antitumor, anti-inflammatory, anti-coagulant, anti-oxidant, and anti-thrombogenic activities. It is a naturally acquired bio-macromolecule with beneficial properties, such as biocompatibility, biodegradability, and immensely low toxicity, making it the center of attention in developing biomaterials for various biomedical applications. The authors have discussed the structure, unique properties, and extraction source of CS in the initial section of this review. Further, the current investigations on applications of CS-based composites in various biomedical fields, focusing on delivering active pharmaceutical compounds, tissue engineering, and wound healing, are discussed critically. In addition, the manuscript throws light on preclinical and clinical studies associated with CS composites. A short section on Chondroitinase ABC has also been canvassed. Finally, this review emphasizes the current challenges and prospects of CS in various biomedical fields.

Elaborated survey in the scope of nanocarriers engineering for boosting chemotherapy cytotoxicity: A meta-analysis study

Cancer is the prime cause of mortality throughout the world. Although the conventional chemotherapeutic agents damage the cancerous cells, they exert prominent injury to the normal cells owing to their lack of specificity. With advances in science, many research studies have been established to boost the cytotoxic effect of the chemotherapeutic agents via innovating novel nano-formulations having different variables. In the current meta-analysis study, combined data from different research articles were gathered for the evidence-based proof of the superiority of drug loaded nanocarriers over their corresponding conventional solutions in boosting the cytotoxic effect of chemotherapy in terms of IC50 values. The meta-analysis was subdivided into three subgroups; nanoparticles versus nanofibers, surface functionalized nanocarriers versus naked ones, and protein versus non-protein-based platforms. The different subgroups interestingly showed distinct scoring outcome data paving the road for cytotoxicity enhancement of the anti-cancer drugs in an evidence-based manner.

Say no to drugs: Bioactive macromolecular therapeutics without conventional drugs

The vast majority of nanomedicines (NM) investigated today consists of a macromolecular carrier and a drug payload (conjugated or encapsulated), with a purpose of preferential delivery of the drug to the desired site of action, either through passive accumulation, or by active targeting via ligand-receptor interaction. Several drug delivery systems (DDS) have already been approved for clinical use. However, recent reports are corroborating the notion that NM do not necessarily need to include a drug payload, but can exert biological effects through specific binding/blocking of important target proteins at the site of action. The seminal work of Kopeček et al. on N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers containing biorecognition motifs (peptides or oligonucleotides) for crosslinking cell surface non-internalizing receptors of malignant cells and inducing their apoptosis, without containing any low molecular weight drug, led to the definition of a special group of NM, termed Drug-Free Macromolecular Therapeutics (DFMT). Systems utilizing this approach are typically designed to employ pendant targeting-ligands on the same macromolecule to facilitate multivalent interactions with receptors. The lack of conventional small molecule drugs reduces toxicity and adverse effects at off-target sites. In this review, we describe different types of DFMT that possess biological activity without attached low molecular weight drugs. We classified the relevant research into several groups by their mechanisms of action, and compare the advantages and disadvantages of these different approaches. We show that identification of target sites, specificity of attached targeting ligands, binding affinity and the synthesis of carriers of defined size and ligand spacing are crucial aspects of DFMT development. We further discuss how knowledge in the field of NM accumulated in the past few decades can help in the design of a successful DFMT to speed up the translation into clinical practice.

Chondroitin sulfate derived theranostic and therapeutic nanocarriers for tumor-targeted drug delivery

The standard chemotherapy is facing the challenges of lack of cancer selectivity and development of drug resistance. Currently, with the application of nanotechnology, the rationally designed nanocarriers of chondroitin sulfate (CS) have been fabricated and their unique features of low toxicity, biocompatibility, and active and passive targeting made them drug delivery vehicles of the choice for cancer therapy. The hydrophilic and anionic CS could be incorporated as a building block into- or decorated on the surface of nanoformulations. Micellar nanoparticles (NPs) self-assembled from amphiphilic CS-drug conjugates and CS-polymer conjugates, polyelectrolyte complexes (PECs) and nanogels of CS have been widely implicated in cancer directed therapy. The surface modulation of organic, inorganic, lipid and metallic NPs with CS promotes the receptor-mediated internalization of NPs to the tumor cells. The potential contribution of CS and CS-proteoglycans (CSPGs) in the pathogenesis of various cancer types, and CS nanocarriers in immunotherapy, radiotherapy, sonodynamic therapy (SDT) and photodynamic therapy (PDT) of cancer are summarized in this review paper.