Carbamoylated Guanidine-Containing Polymers for Non-Covalent Functional Protein Delivery in Serum-Containing Media

Recent advances in nanoagents delivery system-based phototherapy for osteosarcoma treatment

Osteosarcoma (OS) is a prevalent and highly malignant bone tumor, characterized by its aggressive nature, invasiveness, and rapid progression, contributing to a high mortality rate, particularly among adolescents. Traditional treatment modalities, including surgical resection, radiotherapy, and chemotherapy, face significant challenges, especially in addressing chemotherapy resistance and managing postoperative recurrence and metastasis. Phototherapy (PT), encompassing photodynamic therapy (PDT) and photothermal therapy (PTT), offers unique advantages such as low toxicity, minimal drug resistance, selective destruction, and temporal control, making it a promising approach for the clinical treatment of various malignant tumors. Constructing multifunctional delivery systems presents an opportunity to effectively combine tumor PDT, PTT, and chemotherapy, creating a synergistic anti-tumor effect. This review aims to consolidate the progress in the application of novel delivery system-mediated phototherapy in osteosarcoma. By summarizing advancements in this field, the objective is to propose a rational combination therapy involving targeted delivery systems and phototherapy for tumors, thereby expanding treatment options and enhancing the prognosis for osteosarcoma patients. In conclusion, the integration of innovative delivery systems with phototherapy represents a promising avenue in osteosarcoma treatment, offering a comprehensive approach to overcome challenges associated with conventional treatments and improve patient outcomes.

Engineering Nucleotidoproteins for Base-Pairing-Assisted Cytosolic Delivery and Genome Editing

Protein therapeutics targeting intracellular machineries hold profound potential for disease treatment, and hence robust cytosolic protein delivery technologies are imperatively demanded. Inspired by the super-negatively charged, nucleotide-enriched structure of nucleic acids, adenylated pro-proteins (A-proteins) with dramatically enhanced negative surface charges have been engineered for the first time via facile green synthesis. Then, thymidine-modified polyethyleneimine is developed, which exhibits strong electrostatic attraction, complementary base pairing, and hydrophobic interaction with A-proteins to form salt-resistant nanocomplexes with robust cytosolic delivery efficiencies. The acidic endolysosomal environment enables traceless restoration of the A-proteins and consequently promotes the intracellular release of the native proteins. This strategy shows high efficiency and universality for a variety of proteins with different molecular weights and isoelectric points in mammalian cells. Moreover, it enables highly efficient delivery of CRISPR-Cas9 ribonucleoproteins targeting fusion oncogene EWSR1-FLI1, leading to pronounced anti-tumor efficacy against Ewing sarcoma. This study provides a potent and versatile platform for cytosolic protein delivery and gene editing, and may benefit the development of protein pharmaceuticals.

Functional L-Arginine Derivative as an Efficient Vector for Intracellular Protein Delivery for Potential Cancer Therapy

The utilization of cytosolic protein delivery is a promising approach for treating various diseases by replacing dysfunctional proteins. Despite the development of various nanoparticle-based intracellular protein delivery methods, the complicated chemical synthesis of the vector, loading efficiency and endosomal escape efficiency of proteins remain a great challenge. Recently, 9-fluorenylmethyloxycarbonyl (Fmoc)-modified amino acid derivatives have been used to self-assemble into supramolecular nanomaterials for drug delivery. However, the instability of the Fmoc group in aqueous medium restricts its application. To address this issue, the Fmoc ligand neighboring arginine was substituted for dibenzocyclooctyne (DBCO) with a similar structure to Fmoc to obtain stable DBCO-functionalized L-arginine derivative (DR). Azide-modified triethylamine (crosslinker C) was combined with DR to construct self-assembled DRC via a click chemical reaction for delivering various proteins, such as BSA and saporin (SA), into the cytosol of cells. The hyaluronic-acid-coated DRC/SA was able to not only shield the cationic toxicity, but also enhance the intracellular delivery efficiency of proteins by targeting CD44 overexpression on the cell membrane. The DRC/SA/HA exhibited higher growth inhibition efficiency and lower IC₅₀ compared to DRC/SA toward various cancer cell lines. In conclusion, DBCO-functionalized L-arginine derivative represents an excellent potential vector for protein-based cancer therapy.

Intracellular delivery of therapeutic proteins. New advancements and future directions

Achieving the full potential of therapeutic proteins to access and target intracellular receptors will have enormous benefits in advancing human health and fighting disease. Existing strategies for intracellular protein delivery, such as chemical modification and nanocarrier-based protein delivery approaches, have shown promise but with limited efficiency and safety concerns. The development of more effective and versatile delivery tools is crucial for the safe and effective use of protein drugs. Nanosystems that can trigger endocytosis and endosomal disruption, or directly deliver proteins into the cytosol, are essential for successful therapeutic effects. This article aims to provide a brief overview of the current methods for intracellular protein delivery to mammalian cells, highlighting current challenges, new developments, and future research opportunities.

Guanidinium-Rich Lipopeptide-Based Nanoparticle Enables Efficient Gene Editing in Skeletal Muscles

Genome editing mediated by the CRISPR-Cas system holds great promise for the treatment of genetic diseases. However, safe and efficient in vivo delivery of CRISPR genome editing machinery remains a challenge. Here, we report a lipopeptide-based nanoparticle (LNP) that can efficiently deliver the CRISPR Cas9/sgRNA ribonucleoprotein (RNP) and enable efficient genome editing both in vitro and in vivo. An artificial lipopeptide, GD-LP, was constructed by linking a hydrophilic guanidinium-rich head to an oleic acid-based hydrophobic tail via a disulfide bond. LNP formed by the self-assembly of GD-LP can easily form a complex with RNP with a loading content of up to 20 wt %. The resulting RNP-LNP nanocomplex led to 72.6% gene editing efficiency in GFP-HEK cells with negligible cytotoxicity. The LNP also showed significantly higher transfection efficiencies than Lipofectamine 2000 for the delivery of mRNA in NIH 3T3 and RAW 264.7 and the delivery of plasmid DNA in B78 cells. In vivo studies showed that intramuscular injection of the RNP-LNP nanocomplex in Ai14 mice induced efficient gene editing in muscular tissues. Moreover, the delivery of Cas9 RNP and donor DNA by LNP (i.e., RNP/ssODN-LNP nanocomplex) restored dystrophin expression, reduced skeletal muscle fibrosis, and significantly improved muscle strength in a Duchenne muscular dystrophy (DMD) mouse model.

A light-activated polymer with excellent serum tolerance for intracellular protein delivery

The design of efficient materials for intracellular protein delivery has attracted great interest in recent years; however, most current materials for this purpose are limited by poor serum stability due to the early release of cargoes triggered by abundant serum proteins. Here, we propose a light-activated crosslinking (LAC) strategy to prepare efficient polymers with excellent serum tolerance for intracellular protein delivery. A cationic dendrimer engineered with photoactivatable O-nitrobenzene moieties co-assembles with cargo proteins via ionic interactions, followed by light activation to yield aldehyde groups on the dendrimer and the formation of imine bonds with cargo proteins. The light-activated complexes show high stability in buffer and serum solutions, but dis-assemble under low pH conditions. As a result, the polymer successfully delivers cargo proteins green fluorescent protein and β-galactosidase into cells with maintained bioactivity even in the presence of 50% serum. The LAC strategy proposed in this study provides a new insight to improve the serum stability of polymers for intracellular protein delivery.

Effects of sidechain isomerism on polymer-based non-covalent protein delivery

We present the importance of functional group isomerism on intracellular protein delivery using polymers containing different isomeric side chains. While the physical properties of polymer/protein complexes are relatively similar, different planarity of the isomers greatly influences the cellular entry efficiency.