Dual-responsive bioconjugates bearing a bifunctional adaptor for robust cytosolic peptide delivery

Nanotherapeutics-mediated restoration of pancreatic homeostasis and intestinal barrier for the treatment of severe acute pancreatitis

Severe acute pancreatitis (SAP) is an inflammatory disease of the pancreas accompanied with intestinal injury, and effective therapeutic modalities are still highly lacking. Herein, a facile and effective nanotherapeutics (pHA@IBNCs) is developed to alleviate pancreatic inflammation and restore intestinal barrier for SAP treatment. Epigallocatechin gallate (EGCG, an anti-oxidant), interleukin-22 (IL-22, an anti-inflammatory and epithelial barrier-protecting cytokine), and bovine serum albumin (a framework protein), are assembled via non-covalent interactions to form nanocomplexes (IBNCs). Then, phenylboronic acid-modified hyaluronic acid (pHA) is synthesized and coated onto IBNCs via formation of the reversible boronate ester bonds to obtain pHA@IBNCs. Upon intravenous injection, pHA@IBNCs could efficiently accumulate at the lesion sites of sodium taurocholate (STC)-induced SAP mice, based on their prolonged blood circulation time and pHA-mediated targeting of activated intestinal epithelial cells and macrophages. Inside the inflammatory microenvironment, over-produced reactive oxygen species (ROS) trigger the shedding of the pHA layer and release of the drug payloads. Thereby, EGCG cooperates with IL-22 to attenuate pancreatitis and restore the intestinal barrier by scavenging ROS, suppressing pro-inflammatory cytokines secretion, and promoting the repair of intestinal epithelia. Such a nano-therapeutic approach targeting multiple pathological events may serve as a promising paradigm for the effective management of SAP.

A Patent Analysis on Nano Drug Delivery Systems

BACKGROUND

A nano drug delivery system is an effective tool for drug delivery and controlled release, which is used for a variety of medical applications. In recent decades, nano drug delivery systems have been significantly developed with the emergence of new nanomaterials and nanotechnologies.

OBJECTIVE

This article aimed to provide insight into the technological development of nano drug delivery systems through patent analysis.

METHODS

3708 patent documents were used for patent analysis after retrieval from the Incopat patent database.

RESULTS

The number of patents on nano drug delivery systems has shown a rapid growth trend in the past two decades. At present, China and the United States have obvious contributions to the number of patents. According to the patent data, the nanomaterials used in nano drug delivery system are mainly inorganic nanomaterials, lipid-based nanomaterials, and macromolecules. In recent years, the highly cited patents (≥14) for nano drug delivery systems mainly involve lipid-based nanomaterials, indicating that their technology is mature and widely used. The inorganic nanomaterials in drug delivery have received increasing attention, and the number of related patents has increased significantly after 2016. The number of highly cited patents in the United States is 250, which is much higher than in other countries.

CONCLUSION

Even after decades of development, nano drug delivery systems remain a hot topic for researchers. The significant increase in patents since 2016 can be attributed to the large number of new patents from China. However, according to the proportion of highly cited patents in total, China's patented technologies in nano drug delivery systems are not advanced enough compared to developed countries, including the United States, Canada, Germany, and France. In the future, research on emerging nanomaterials for nano drug delivery systems, such as inorganic nanomaterials, may focus on developing new materials and optimising their properties. The lipid-based and polymer- based nanomaterials can be continuously improved for the development of new nanomedicines.

Bone-Targeted Fluoropeptide Nanoparticle Inhibits NF-κB Signaling to Treat Osteosarcoma and Tumor-Induced Bone Destruction

Osteosarcoma is a malignant bone cancer usually characterized by symptoms of bone loss due to pathologically enhanced osteoclast activity. Activated osteoclasts enhance bone resorption and promote osteosarcoma cell progression by secreting various cytokines. Intercepting the detrimental interplay between osteoclasts and osteosarcoma cells is considered as an option for osteosarcoma treatment. Here, a bone-targeted fluoropeptide nanoparticle that can inhibit the nuclear factor kappa B (NF-κB) signaling in both osteoclasts and osteosarcoma to address the above issue is developed. The NF-κB essential modulator binding domain (NBD) peptide is conjugated with a fluorous tag to improve its proteolytic stability and intracellular penetration. The NBD peptide is efficiently delivered into cells after fluorination to induce apoptosis of osteocarcoma cells, and inhibits osteoclasts differentiation. The fluorous-tagged NBD peptide is further co-assembled with an oligo (aspartic acid) terminated fluoropeptide to form bone-targeted peptide nanoparticles for osteosarcoma treatment. The targeted nanoparticles efficiently inhibited tumor progression and osteosarcoma-induced bone destruction in vivo. This co-assembled fluoropeptide nanoplatform proposed in this study offers a promising approach for targeted and intracellular delivery of peptide therapeutics in the treatment of various diseases.

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.

Reversible Assembly of Proteins and Phenolic Polymers for Intracellular Protein Delivery with Serum Stability

The design of intracellular delivery systems for protein drugs remains a challenge due to limited delivery efficacy and serum stability. Herein, we propose a reversible assembly strategy to assemble cargo proteins and phenolic polymers into stable nanoparticles for this purpose using a heterobifunctional adaptor (2-formylbenzeneboronic acid). The adaptor is easily decorated on cargo proteins via iminoboronate chemistry and further conjugates with catechol-bearing polymers to form nanoparticles via boronate diester linkages. The nanoparticles exhibit excellent serum stability in culture media but rapidly release the cargo proteins triggered by lysosomal acidity and GSH after endocytosis. In a proof-of-concept animal model, the strategy successfully transports superoxide dismutase to retina via intravitreal injection and efficiently ameliorates the oxidative stress and cellular damage in the retina induced by ischemia-reperfusion (I/R) with minimal adverse effects. The reversible assembly strategy represents a robust and efficient method to develop serum-stable systems for the intracellular delivery of biomacromolecules.

Therapeutic Oligonucleotides: An Outlook on Chemical Strategies to Improve Endosomal Trafficking

The potential of oligonucleotide therapeutics is undeniable as more than 15 drugs have been approved to treat various diseases in the liver, central nervous system (CNS), and muscles. However, achieving effective delivery of oligonucleotide therapeutics to specific tissues still remains a major challenge, limiting their widespread use. Chemical modifications play a crucial role to overcome biological barriers to enable efficient oligonucleotide delivery to the tissues/cells of interest. They provide oligonucleotide metabolic stability and confer favourable pharmacokinetic/pharmacodynamic properties. This review focuses on the various chemical approaches implicated in mitigating the delivery problem of oligonucleotides and their limitations. It highlights the importance of linkers in designing oligonucleotide conjugates and discusses their potential role in escaping the endosomal barrier, a bottleneck in the development of oligonucleotide therapeutics.

Fluorous Tagged Peptides for Intracellular Delivery and Biomedical Imaging

Fluorous tagged peptides have shown promising features for biomedical applications such as drug delivery and multimodal imaging. The bioconjugation of fluoroalkyl ligands onto cargo peptides greatly enhances their proteolytic stability and membrane penetration via a proposed "fluorine effect". The tagged peptides also efficiently deliver other biomolecules such as DNA and siRNA into cells via a co-assembly strategy. The fluoroalkyl chains on peptides with antifouling properties enable efficient gene delivery in the presence of serum proteins. Besides intracellular biomolecule delivery, the amphiphilic peptides can be used to stabilized perfluorocarbon-filled microbubbles for ultrasound imaging. The fluorine nucleus on fluoroalkyls provides intrinsic probes for background-free magnetic resonance imaging. Labeling of fluorous tags with radionuclide 18 F also allows tracing the biodistribution of peptides via positron emission tomography imaging. This mini-review will discuss properties and mechanism of the fluorous tagged peptides in these applications.