Multimeric RGD-Based Strategies for Selective Drug Delivery to Tumor Tissues

Peptide-based CE-SELEX enables convenient isolation of aptamers specifically recognizing CD20-expressing cells

The CD20 antigen is a key target for several diseases including lymphoma and autoimmune diseases. For over 20 years, several monoclonal antibodies were developed to treat CD20-related disorders. As many therapeutic proteins, their clinical use is however limited due to their nature with a costly biotechnological procedure and side effects such as the production of anti-drug neutralizing antibodies. Nucleic acid aptamers have some advantages over mAbs and are currently investigated for clinical use. We herein report the selection of DNA aptamer by using a peptide-based CE-SELEX (Capillary Electrophoresis-Systematic Evolution of Ligands by Exponential Enrichment) method. It was demonstrated that these aptamers bind specifically a CD20-expressing human cell line, with Kd estimated from isothermal titration calorimetry experiments in the micromolar range. This study demonstrates that the CE-SELEX is suitable as alternative method to the conventional Cell-SELEX to discover new cell-targeting compounds.

Humanistic Health Management and Cancer: Associations of Psychology, Nutrition, and Exercise with Cancer Progression and Pathogenesis

The incidence rate of cancer is increasing year by year due to the aging of the population, unhealthy living, and eating habits. At present, surgery and medication are still the main treatments for cancer, without paying attention to the impact of individual differences in health management on cancer. However, increasing evidence suggests that individual psychological status, dietary habits, and exercise frequency are closely related to the risk and prognosis of cancer. The reminder to humanity is that the medical concept of the unified treatment plan is insufficient in cancer treatment, and a personalized treatment plan may become a breakthrough point. On this basis, the concept of "Humanistic Health Management" (HHM) is proposed. This concept is a healthcare plan that focuses on self-health management, providing an accurate and comprehensive evaluation of individual lifestyle habits, psychology, and health status, and developing personalized and targeted comprehensive cancer prevention and treatment plans. This review will provide a detailed explanation of the relationship between psychological status, dietary, and exercise habits, and the regulatory mechanisms of cancer. Intended to emphasize the importance of HHM concept in cancer prevention and better prognostic efficacy, providing new ideas for the new generation of cancer treatment.

Elevating theranostics: The emergence and promise of radiopharmaceutical cell-targeting heterodimers in human cancers

Optimal therapeutic and diagnostic efficacy is essential for healthcare's global mission of advancing oncologic drug development. Accurate diagnosis and detection are crucial prerequisites for effective risk stratification and personalized patient care in clinical oncology. A paradigm shift is emerging with the promise of multi-receptor-targeting compounds. While existing detection and staging methods have demonstrated some success, the traditional approach of monotherapy is being reevaluated to enhance therapeutic effectiveness. Heterodimeric site-specific agents are a versatile solution by targeting two distinct biomarkers with a single theranostic agent. This review describes the innovation of dual-targeting compounds, examining their design strategies, therapeutic implications, and the promising path they present for addressing complex diseases.

RGD peptide in cancer targeting: Benefits, challenges, solutions, and possible integrin-RGD interactions

RGD peptide can be found in cell adhesion and signaling proteins, such as fibronectin, vitronectin, and fibrinogen. RGD peptides' principal function is to facilitate cell adhesion by interacting with integrin receptors on the cell surface. They have been intensively researched for use in biotechnology and medicine, including incorporation into biomaterials, conjugation to medicinal molecules or nanoparticles, and labeling with imaging agents. RGD peptides can be utilized to specifically target cancer cells and the tumor vasculature by engaging with these integrins, improving drug delivery efficiency and minimizing adverse effects on healthy tissues. RGD-functionalized drug carriers are a viable option for cancer therapy as this focused approach has demonstrated promise in the future. Writing a review on the RGD peptide can significantly influence how drugs are developed in the future by improving our understanding of the peptide, finding knowledge gaps, fostering innovation, and making drug design easier.

High-precision targeting and destruction of cancer-associated PDGFR-β+ stromal fibroblasts through self-assembling, protein-only nanoparticles

The need for more effective and precision medicines for cancer has pushed the exploration of new materials appropriate for drug delivery and imaging, and alternative receptors for targeting. Among the most promising strategies, finding suitable cell surface receptors and targeting agents for cancer-associated platelet derived growth factor receptor β (PDGFR-β)+ stromal fibroblasts is highly appealing. As a neglected target, this cell type mechanically and biologically supports the growth, progression, and infiltration of solid tumors in non-small cell lung, breast, pancreatic, and colorectal cancers. We have developed a family of PDGFR-β-targeted nanoparticles based on biofabricated, self-assembling proteins, upon hierarchical and iterative selective processes starting from four initial candidates. The modular protein PDGFD-GFP-H6 is well produced in recombinant bacteria, resulting in structurally robust oligomeric particles that selectively penetrates into PDGFR-β+ stromal fibroblasts in a dose-dependent manner, by means of the PDGFR-β ligand PDGFD. Upon in vivo administration, these GFP-carrying protein nanoparticles precisely accumulate in tumor tissues and enlighten them for IVIS observation. When GFP is replaced by a microbial toxin, selective tumor tissue destruction is observed associated with a significant reduction in tumor volume growth. The presented data validate the PDGFR-β/PDGFD pair as a promising toolbox for targeted drug delivery in the tumor microenvironment and oligomeric protein nanoparticles as a powerful instrument to mediate highly selective biosafe targeting in cancer through non-cancer cells. STATEMENT OF SIGNIFICANCE: We have developed a transversal platform for nanoparticle-based drug delivery into cancer-associated fibroblasts. This is based on the engineered modular protein PDGFD-GFP-H6 that spontaneously self-assemble and selectively penetrates into PDGFR-β+ stromal fibroblasts in a dose-dependent manner, by means of the PDGFR-β ligand PDGFD. In vivo, these protein nanoparticles accumulate in tumor and when incorporating a microbial toxin, they destroy tumor tissues with a significant reduction in tumor volume, in absence of side toxicities. The data presented here validate the PDGFR-β/PDGFD pair as a fully versatile toolbox for targeted drug delivery in the tumor microenvironment intended as a synergistic treatment.

LA67 Liposome-Loaded Thermo-Sensitive Hydrogel with Active Targeting for Efficient Treatment of Keloid via Peritumoral Injection

A keloid is a benign tumor manifested as abnormal fibroplasia on the surface of the skin. Curing keloids has become a major clinical challenge, and searching for new treatments and medications has become critical. In this study, we developed a LA67 liposome-loaded thermo-sensitive hydrogel (LA67-RL-Gel) with active targeting for treating keloids via peritumoral injection and explored the anti-keloid mechanism. Firstly, Arg-Gly-Asp (RGD) peptide-modified liposomes (LA67-RL) loaded with LA67 were prepared with a particle size of 105.9 nm and a Zeta potential of -27.4 mV, and an encapsulation efficiency of 89.6 ± 3.7%. We then constructed a thermo-sensitive hydrogel loaded with LA67-RL by poloxamer 407 and 188. The formulation was optimized through the Box-Behnken design, where the impact of the proportion of the ingredients on the quality of the hydrogel was evaluated entirely. The optimal formulation was 20.7% P407 and 2.1% P188, and the gelation time at 37 °C was 9.5 s. LA67-RL-Gel slowly released 92.2 ± 0.8% of LA67 at pH 6.5 PBS for 72 h. LA67-RL-Gel increased adhesion with KF cells; increased uptake; promoted KF cells apoptosis; inhibited cell proliferation; reduced α-SMA content; decreased collagen I, collagen III, and fibronectin deposition; inhibited angiogenesis; and modulated the keloid microenvironment, ultimately exerting anti-keloid effects. In summary, this simple, low-cost, and highly effective anti-keloid liposome hydrogel provides a novel approach for treating keloids and deserves further development.

Recent Advances of Cell-Penetrating Peptides and Their Application as Vectors for Delivery of Peptide and Protein-Based Cargo Molecules

Peptides and proteins, two important classes of biomacromolecules, play important roles in the biopharmaceuticals field. As compared with traditional drugs based on small molecules, peptide- and protein-based drugs offer several advantages, although most cannot traverse the cell membrane, a natural barrier that prevents biomacromolecules from directly entering cells. However, drug delivery via cell-penetrating peptides (CPPs) is increasingly replacing traditional approaches that mediate biomacromolecular cellular uptake, due to CPPs' superior safety and efficiency as drug delivery vehicles. In this review, we describe the discovery of CPPs, recent developments in CPP design, and recent advances in CPP applications for enhanced cellular delivery of peptide- and protein-based drugs. First, we discuss the discovery of natural CPPs in snake, bee, and spider venom. Second, we describe several synthetic types of CPPs, such as cyclic CPPs, glycosylated CPPs, and D-form CPPs. Finally, we summarize and discuss cell membrane permeability characteristics and therapeutic applications of different CPPs when used as vehicles to deliver peptides and proteins to cells, as assessed using various preclinical disease models. Ultimately, this review provides an overview of recent advances in CPP development with relevance to applications related to the therapeutic delivery of biomacromolecular drugs to alleviate diverse diseases.