Harnessing Bifunctional Ferritin with Kartogenin Loading for Mesenchymal Stem Cell Capture and Enhancing Chondrogenesis in Cartilage Regeneration

Novel engineered HER2 specific recombinant protein nanocages for targeted drug delivery

Protein nanocages resemble natural biomimetic carriers and can be engineered to act as targeted delivery systems, making them an attractive option for various drug delivery and biomedical applications. Our research investigated the genetic link of a specific anti-HER2 peptide (LTVSPWY) to the exposed N-terminal region of the maize (Zea mays) ferritin 1 (ZmFer1) protein nanocage, employing either a 7-amino acid (for LTVS-ZmFer1) or 16-amino acid (for LTVS-L-ZmFer1) linker. We utilized a heat treatment method to load the chemotherapeutic drug doxorubicin into the protein nanocage. The construct with the longer linker (LTVS-L) produced a greater amount of soluble protein nanocage and was selected for further experiments. The average size, polydispersity index, and zeta potential of the engineered protein nanocage were 19.01 nm, 0.168, and - 2.13 mV, respectively. The LTVS-L-ZmFer1 protein nanocage exhibited excellent thermal stability, withstanding temperatures up to 100 °C with only partial denaturation. Furthermore, we observed that cellular uptake of the LTVS-L-ZmFer1 protein nanocages in HER2-positive breast cancer cells was significantly higher compared to ZmFer1 after labeling with FITC (fluorescein isothiocyanate) (P-value = 0.0001). In addition, we observed a significant decrease in the viability of SKBR3 cells when treated with DOX-loaded LTVS-L-ZmFer1 protein nanocages compared to cells treated with DOX-loaded ZmFer1 protein nanocages. Therefore, this new treatment strategy may prove to be an effective way to reduce both the side effects and toxicity associated with conventional cancer treatments in patients with HER2-positive breast cancer.

A SU6668 pure nanoparticle-based eyedrops: toward its high drug Accumulation and Long-time treatment for corneal neovascularization

Corneal neovascularization (CNV) is one of the common blinding factors worldwide, leading to reduced vision or even blindness. However, current treatments such as surgical intervention and anti-VEGF agent therapy still have some shortcomings or evoke some adverse effects. Recently, SU6668, an inhibitor targeting angiogenic tyrosine kinases, has demonstrated growth inhibition of neovascularization. But the hydrophobicity and low ocular bioavailability limit its application in cornea. Hereby, we proposed the preparation of SU6668 pure nanoparticles (NanoSU6668; size ~135 nm) using a super-stable pure-nanomedicine formulation technology (SPFT), which possessed uniform particle size and excellent aqueous dispersion at 1 mg/mL. Furthermore, mesenchymal stem cell membrane vesicle (MSCm) was coated on the surface of NanoSU6668, and then conjugated with TAT cell penetrating peptide, preparing multifunctional TAT-MSCm@NanoSU6668 (T-MNS). The T-MNS at a concentration of 200 µg/mL was treated for CNV via eye drops, and accumulated in blood vessels with a high targeting performance, resulting in elimination of blood vessels and recovery of cornea transparency after 4 days of treatment. Meanwhile, drug safety test confirmed that T-MNS did not cause any damage to cornea, retina and other eye tissues. In conclusion, the T-MNS eye drop had the potential to treat CNV effectively and safely in a low dosing frequency, which broke new ground for CNV theranostics.

Temporal control in shell-core structured nanofilm for tracheal cartilage regeneration: synergistic optimization of anti-inflammation and chondrogenesis

Cartilage tissue engineering offers hope for tracheal cartilage defect repair. Establishing an anti-inflammatory microenvironment stands as a prerequisite for successful tracheal cartilage restoration, especially in immunocompetent animals. Hence, scaffolds inducing an anti-inflammatory response before chondrogenesis are crucial for effectively addressing tracheal cartilage defects. Herein, we develop a shell-core structured PLGA@ICA-GT@KGN nanofilm using poly(lactic-co-glycolic acid) (PLGA) and icariin (ICA, an anti-inflammatory drug) as the shell layer and gelatin (GT) and kartogenin (KGN, a chondrogenic factor) as the core via coaxial electrospinning technology. The resultant PLGA@ICA-GT@KGN nanofilm exhibited a characteristic fibrous structure and demonstrated high biocompatibility. Notably, it showcased sustained release characteristics, releasing ICA within the initial 0 to 15 days and gradually releasing KGN between 11 and 29 days. Subsequent in vitro analysis revealed the potent anti-inflammatory capabilities of the released ICA from the shell layer, while the KGN released from the core layer effectively induced chondrogenic differentiation of bone marrow stem cells (BMSCs). Following this, the synthesized PLGA@ICA-GT@KGN nanofilms were loaded with BMSCs and stacked layer by layer, adhering to a 'sandwich model' to form a composite sandwich construct. This construct was then utilized to repair circular tracheal defects in a rabbit model. The sequential release of ICA and KGN facilitated by the PLGA@ICA-GT@KGN nanofilm established an anti-inflammatory microenvironment before initiating chondrogenic induction, leading to effective tracheal cartilage restoration. This study underscores the significance of shell-core structured nanofilms in temporally regulating anti-inflammation and chondrogenesis. This approach offers a novel perspective for addressing tracheal cartilage defects, potentially revolutionizing their treatment methodologies.

Advancements of the Molecular Directed Design and Structure-Activity Relationship of Ferritin Nanocage

Ferritin nanocages possess remarkable structural properties and biological functions, making them highly attractive for applications in functional materials and biomedicine. This comprehensive review presents an overview of the molecular characteristics, extraction and identification of ferritin, ferritin receptors, as well as the advancements in the directional design of high-order assemblies of ferritin and the applications based on its unique structural properties. Specifically, this Review focuses on the regulation of ferritin assembly from one to three dimensions, leveraging the symmetry of ferritin and modifications on key interfaces. Furthermore, it discusses targeted delivery of nutrition and drugs through facile loading and functional modification of ferritin. The aim of this Review is to inspire the design of micro/nano functional materials using ferritin and the development of nanodelivery vehicles for nutritional fortification and disease treatment.

Kartogenin potentially protects temporomandibular joints from collagenase-induced osteoarthritis via core binding factor β and runt-related transcription factor 1 binding - A rat model study

Background/purpose

Temporomandibular joint (TMJ) osteoarthritis (TMJOA) is a chronic disease with progressive destruction of articular cartilage. This study aimed to explore the therapeutic effects of kartogenin on TMJOA via promoting the binding of core binding factor β (CBFβ) and runt-related transcription factor 1 (RUNX1).

Materials and methods

Type II collagenase was injected into 35 8-week-old male Sprague Dawley rat TMJs to establish the TMJOA model. Kartogenin, or the CBFβ-RUNX1 complex inhibitor (Ro5-3335), was also delivered via intra-articular injection. Subchondral bone was analyzed by MicroCT. The hematoxylin-eosin, Safranin O, and toluidine blue O staining were used to observe histopathology. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA), caspase-3 (CASP3), interleukin-1β (IL-1β), and collagen II (COL2) was performed.

Results

TMJOA was established in rats by intra-articular injection of type II collagenase. The condylar cartilage and subchondral bone were damaged, with decreased PCNA and COL2 and increased CASP3 and IL-1 (P < .001). Compared with the OA group, kartogenin alleviated the destruction of cartilage and subchondral bone, rescued the expression of PCNA and COL2, and decreased the expression of CASP3 and IL-1β (P < .01). Ro5-3335 did not aggravate the pathology of TMJOA but neutralized the therapeutic effects of kartogenin on TMJOA.

Conclusion

Kartogenin has a potential therapeutic effect on TMJOA via promoting the CBFβ-RUNX1 binding.

Local Drug Delivery Techniques for Triggering Immunogenic Cell Death

Immunogenic cell death (ICD), a dying state of the cells, encompasses the changes in the conformations of cell surface and the release of damage-associated molecular patterns, which could initiate an adaptive immune response by stimulating the dendritic cells to present antigens to T cells. Advancements in biomaterials, nanomedicine, and micro- and nano-technologies have facilitated the development of effective ICD inducers, but the potential toxicity of these vesicles encountered in drug delivery via intravenous administration hampers their further application. As alternatives, the local drug delivery systems have gained emerging attention due to their ability to prolong the retention of high payloads at the lesions, sequester drugs from harsh environments, overcome biological barriers to exert optimal efficacy, and minimize potential side effects to guarantee bio-safety. Herein, a brief overview of the local drug delivery techniques used for ICD inducers is provided, explaining how these techniques broaden, alter, and enhance the therapeutic capability while circumventing systemic toxicity at the same time. The historical context and prominent examples of the local administration of ICD inducers are introduced. The complexities, potential pitfalls, and opportunities for local drug delivery techniques in cancer immunotherapy are also discussed.

Early diagnosis of heterotopic ossification with a NIR fluorescent probe by targeting type II collagen

Heterotopic ossification (HO) is a devastating sequela in which the pathologic extracellular matrix of the cartilage and bone forms abnormally in soft tissues following traumatic injuries or orthopaedic surgeries. Early treatment is essential for inhibiting the progression of HO but is currently limited by the absence of sensitive and specific early diagnosis. Herein, this study exploits the enrichment of type II collagen (Col2a1) in the HO cartilage formation stage towards developing a near-infrared (NIR) probe for early HO diagnosis, namely WL-808 by conjugating a Col2a1-binding peptide (WYRGRL) and a cyanine dye (IR-808). WL-808 exhibits high specificity for targeting the cartilage in vitro and in vivo with no apparent cytotoxicity. The NIR signal of WL-808 can be detected in the HO cartilage lesions as early as 1 week after injury when micro-CT cannot show any ectopic bone formation. Moreover, the probe is rarely distributed in the normal knee articular cartilage in vivo via the intravenous administration method. Taken together, WL-808 demonstrates great potential in early HO diagnosis under NIR imaging, facilitating early HO prophylaxis and treatment in the clinic.

Ferritin-based nanomedicine for disease treatment

Ferritin is an endogenous protein which is self-assembled by 24 subunits into a highly uniform nanocage structure. Due to the drug-encapsulating ability in the hollow inner cavity and abundant modification sites on the outer surface, ferritin nanocage has been demonstrated great potential to become a multi-functional nanomedicine platform. Its good biocompatibility, low toxicity and immunogenicity, intrinsic tumor-targeting ability, high stability, low cost and massive production, together make ferritin nanocage stand out from other nanocarriers. In this review, we summarized ferritin-based nanomedicine in field of disease diagnosis, treatment and prevention. The different types of drugs to be loaded in ferritin, as well as drug-loading methods were classified. The strategies for site-specific and non-specific functional modification of ferritin were investigated, then the application of ferritin for disease imaging, drug delivery and vaccine development were discussed. Finally, the challenges restricting the clinical translation of ferritin-based nanomedicines were analyzed.

Brain-Targeted HFn-Cu-REGO Nanoplatform for Site-Specific Delivery and Manipulation of Autophagy and Cuproptosis in Glioblastoma

Durable glioblastoma multiforme (GBM) management requires long-term chemotherapy after surgery to eliminate remaining cancerous tissues. Among chemotherapeutics, temozolomide is considered as the first-line drug for GBM therapy, but the treatment outcome is not satisfactory. Notably, regorafenib, an oral multi-kinase inhibitor, has been reported to exert a markedly superior effect on GBM suppression compared with temozolomide. However, poor site-specific delivery and bioavailability significantly restrict the efficient permeability of regorafenib to brain lesions and compromise its treatment efficacy. Therefore, human H-ferritin (HFn), regorafenib, and Cu²⁺ are rationally designed as a brain-targeted nanoplatform (HFn-Cu-REGO NPs), fulfilling the task of site-specific delivery and manipulating autophagy and cuproptosis against GBM. Herein, HFn affords a preferential accumulation capacity to GBM due to transferrin receptor 1 (TfR1)-mediated active targeting and pH-responsive delivery behavior. Moreover, regorafenib can inhibit autophagosome-lysosome fusion, resulting in lethal autophagy arrest in GBM cells. Furthermore, Cu²⁺ not only facilitates the encapsulation of regorafenib to HFn through coordination interaction but also disturbs copper homeostasis for triggering cuproptosis, resulting in a synergistical effect with regorafenib-mediated lethal autophagy arrest against GBM. Therefore, this work may broaden the clinical application scope of Cu²⁺ and regorafenib in GBM treatment via modulating autophagy and cuproptosis.

Modification of mesenchymal stem cells for cartilage-targeted therapy

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the destruction of the articular cartilage, sclerosis of the subchondral bone, and joint dysfunction. Its pathogenesis is attributed to direct damage and mechanical destruction of joint tissues. Mesenchymal stem cells (MSCs), suggested as a potential strategy for the treatment of OA, have shown therapeutic effects on OA. However, the specific fate of MSCs after intraarticular injection, including cell attachment, proliferation, differentiation, and death, is still unclear, and there is no guarantee that stem cells can be retained in the cartilage tissue to enact repair. Direct homing of MSCs is an important determinant of the efficacy of MSC-based cartilage repair. Recent studies have revealed that the unique homing capacity of MSCs and targeted modification can improve their ability to promote tissue regeneration. Here, we comprehensively review the homing effect of stem cells in joints and highlight progress toward the targeted modification of MSCs. In the future, developments of this targeting system that accelerate tissue regeneration will benefit targeted tissue repair.

Magnetically Guided Intracartilaginous Delivery of Kartogenin Improves Stem Cell-Targeted Degenerative Arthritis Therapy

Background

Degenerative joint disease or osteoarthritis (OA) is a leading cause of disability worldwide. Intra-articular injection is the mainstay nonsurgical treatment for OA. However, dense cartilage and a lack of vasculature often limit the ability of drugs to reach cell or tissue targets at the concentrations necessary to elicit the desired biological response. Kartogenin (KGN), a small molecular compound, possesses a strong capacity to promote chondrogenic differentiation of mesenchymal stem cells (MSCs). However, the rapid clearance of KGN from the intra-articular cavity limits its feasibility.

Materials and Methods

We constructed a magnetically guided biodegradable nanocarrier system (MNP) which enabled intracartilaginous delivery of KGN to promote chondrogenic differentiation by MSCs embedded within the articular matrix. Moreover, in preclinical models of OA, KGN-loaded MNPs exhibited increased tissue penetration and retention within the joint matrix under external magnetic guidance.

Results

Histological examination showed that compared with KGN alone, KGN-loaded MNPs enhanced chondrogenic differentiation and improved the structural integrity of both articular cartilage and subchondral bone.

Conclusion

This study demonstrates a practical method for intracartilaginous delivery using engineered nanocarriers, thus providing a new strategy to improve the efficacy of molecular therapeutic agents in the treatment of OA.