Peptide-based CAR-NK cells: A novel strategy for the treatment of solid tumors

CAR-T cell therapy has been proven to be effective on hematological tumors, although graft-versus-host disease and cytokine release syndrome(CRS) limit its application to a certain extent. However, CAR-T therapy for solid tumors met challenges, among which the lack of tumor-specific antigens (TSA) and immunosuppressive tumor microenvironment (TME) are the most important factors. CAR-NK could be a good alternative to CAR-T in some ways since they can induce mild CRS and are independent of HLA-matching, but the efficacy of CAR-NKs remains limited in solid tumors. CAR cells armed with multiple tumor targeting molecules may obtain higher therapeutic efficacy against solid tumors. Due to large molecular weight, multivalent scFvs cannot be displayed efficiently on T cells and the high affinity of scFv to the target makes it easy to cause on-target, off-tumor(OTOT) toxicity. Peptides with low molecular weight and slightly lower affinity than scFvs allow immune cells to display multiple peptides to increase killing ability and reduce OTOT toxicity. In our study, peptide-based CAR-NK cells were designed to solve the dilemma of CAR-T in solid tumors. Firstly, the peptide-based CAR-NK92MI cells with A1 peptide were constructed and their inhibitory effects on the growth of A549 tumor cells were identified. Secondly, the tri-specific CAR-NK92MI cells with peptides that simultaneously targeted PD-L1, EGFR and VEGFR2 were developed for the combinatory therapy. Tri-specific CAR-NK92MI exhibited comparable killing activities to scFv-based CAR-NK92MI. Moreover, peptide-based CAR NK92MI mitigated OTOT toxicity. Our study implied that peptide-based CAR-NKs could behave as promising tools in solid tumor.

Microarray Chip-Based High-Throughput Screening of Neurofilament Light Chain Self-Assembling Peptide for Noninvasive Monitoring of Alzheimer's Disease

Alzheimer's disease (AD) starts decades before cognitive symptoms develop. Easily accessible and cost-effective biomarkers that accurately reflect AD pathology are essential for both monitoring and therapeutics of AD. Neurofilament light chain (NfL) levels in blood and cerebrospinal fluid are increased in AD more than a decade before the expected onset, thus providing one of the most promising blood biomarkers for monitoring of AD. The clinical practice of employing single-molecule array (Simoa) technology for routine use in patient care is limited by the high costs. Herein, we developed a microarray chip-based high-throughput screening method and screened an attractive self-assembling peptide targeting NfL. Through directly "imprinting" and further analyzing the sequences, morphology, and affinity of the identified self-assembling peptides, the Pep-NfL peptide nanosheet with high binding affinity toward NfL (KD = 1.39 × 10-9 mol/L), high specificity, and low cost was characterized. The superior binding ability of Pep-NfL was confirmed in AD mouse models and cell lines. In the clinical setting, the Pep-NfL peptide nanosheets hold great potential for discriminating between patients with AD (P < 0.001, n = 37), mild cognitive impairment (P < 0.05, n = 26), and control groups (n = 30). This work provides a high-throughput, high-sensitivity, and economical system for noninvasive tracking of AD to monitor neurodegeneration at different stages of disease. The obtained Pep-NfL peptide nanosheet may be useful for assessing dynamic changes in plasma NfL concentrations to evaluate disease-modifying therapies as a surrogate end point of neurodegeneration in clinical trials.

Ultrasound Microvessel Visualization in Cervical Cancer: Association Between Novel Ultrasound Techniques and Histologic Microvessel Densities

OBJECTIVE

The aim of the work described here was to evaluate the feasibility of superb microvascular imaging (SMI) and vascular endothelial growth factor receptor 2 (VEGFR2)-targeted microbubble (MBVEGFR2)-based ultrasound molecular imaging (USMI) for visualizing microvessels in cervical cancer.

METHODS

Hela cells were used to establish subcutaneous cervical cancer models. SMI and MBVEGFR2-based USMI were performed, and the results were compared with intratumoral microvessel density (MVD) in four groups based on tumor diameter (<3 mm, 3-5 mm, 5-7 mm and ≥7 mm). The vascularization index (VI, %) was evaluated for SMI, and the normalized intensity difference (NID) for USMI.

RESULTS

Tumors with diameters ranging from 3 to 5 mm had the highest VI (39.07 ± 1.58) in SMI, and VI significantly decreased with increasing tumor size (all p values <0.001). The strongest signal intensity was observed in very early tumors (d < 3 mm: 43.80 ± 3.58%) after MBVEGFR2 administration; the NID gradually decreased with increasing diameter of tumors (all p values = 0.007). However, no significant differences were observed in NID after administration of non-targeted (control) microbubbles (MBCon) (all p values = 0.125). MBVEGFR2-based USMI had the strongest correlation with MVD in displaying microvessels of cervical cancer compared with SMI and MBCon (R2 = 0.78 vs. R2 = 0.40 and R2 = 0.38).

CONCLUSION

These findings validate the superiority and accuracy of MBVEGFR2-based USMI for microvessel imaging and monitoring of angiogenesis in cervical cancer compared with SMI and MBCon. Nonetheless, SMI remains an alternative to microvessel imaging when ultrasonic contrast agent use is contraindicated.

VEGFR2 targeted microbubble-based ultrasound molecular imaging improving the diagnostic sensitivity of microinvasive cervical cancer

BACKGROUND

The current diagnostic methods of microinvasive cervical cancer lesions are imaging diagnosis and pathological evaluation. Pathological evaluation is invasive and imaging approaches are of extremely low diagnostic performance. There is a paucity of effective and noninvasive imaging approaches for these extremely early cervical cancer during clinical practice. In recent years, ultrasound molecular imaging (USMI) with vascular endothelial growth factor receptor type 2 (VEGFR2) targeted microbubble (MB_VEGFR2) has been reported to improve the early diagnosis rates of breast cancer (including ductal carcinoma in situ), pancreatic cancer and hepatic micrometastases. Herein, we aimed to assess the feasibility of MB_VEGFR2-based USMI in extremely early cervical cancer detection to provide an accurate imaging modality for microinvasive cervical cancer (International Federation of Gynecology and Obstetrics (FIGO) Stage IA1 and IA2).

RESULTS

We found MB_VEGFR2-based USMI could successfully distinguish extremely early lesions in diameter < 3 mm from surrounding normal tissues (all P < 0.05), and the sensitivity gradually decreased along with increasing tumor diameter. Moreover, normalized intensity difference (NID) values showed a good linear correlation with microvessel density (MVD) (R² = 0.75). In addition, all tumors could not be identified from surrounding muscles in subtracted ultrasound images when mice were administered MB_Con.

CONCLUSIONS

Overall, MB_VEGFR2-based USMI has huge potential for clinical application for the early detection of microinvasive cervical cancer (FIGO Stage IA1 and IA2), providing the foothold for future studies on the imaging screening of this patient population.

Peptide functionalized liposomes for receptor targeted cancer therapy

Most clinically approved cancer therapies are potent and toxic small molecules that are limited by severe off-target toxicities and poor tumor-specific localization. Over the past few decades, attempts have been made to load chemotherapies into liposomes, which act to deliver the therapeutic agent directly to the tumor. Although liposomal encapsulation has been shown to decrease toxicity in human patients, reliance on passive targeting via the enhanced permeability and retention (EPR) effect has left some of these issues unresolved. Recently, investigations into modifying the surface of liposomes via covalent and/or electrostatic functionalization have offered mechanisms for tumor homing and subsequently controlled chemotherapeutic delivery. A wide variety of biomolecules can be utilized to functionalize liposomes such as proteins, carbohydrates, and nucleic acids, which enable multiple directions for cancer cell localization. Importantly, when nanoparticles are modified with such molecules, care must be taken as not to inactivate or denature the ligand. Peptides, which are small proteins with <30 amino acids, have demonstrated the exceptional ability to act as ligands for transmembrane protein receptors overexpressed in many tumor phenotypes. Exploring this strategy offers a method in tumor targeting for cancers such as glioblastoma multiforme, pancreatic, lung, and breast based on the manifold of receptors overexpressed on various tumor cell populations. In this review, we offer a comprehensive summary of peptide-functionalized liposomes for receptor-targeted cancer therapy.

Peptide-functionalized liposomes as therapeutic and diagnostic tools for cancer treatment

Clinically efficacious medication in anticancer therapy has been successfully designed with liposome-based nanomedicine. The liposomal formulation in cancer drug delivery can be facilitated with a functionalized peptide that mediates the specific drug delivery opportunities with increased drug penetrability, specific accumulation in the targeted site, and enhanced therapeutic efficacy. This review aims to focus on recent advances in peptide-functionalized liposomal formulation techniques in cancer diagnosis and treatment regarding recently published literature. It also will highlight different aspects of novel liposomal formulation techniques that incorporate surface functionalization with peptides for better anticancer effect and current challenges in peptide-functionalized liposomal drug formulation.

Tethering functionality to lipid interfaces by a fast, simple and controllable post synthesis method

HYPOTHESIS

Liposomes require careful control of the surface design to ensure colloidal stability in complex matrices and target-specific binding to desired receptor units. Ideally, surface functionalization should be smart and controllable in terms of composition which is seldomly achieved by conventional methods. Therefore, a new strategy (insertion method) was developed and compared to the standard method (modification post-synthesis) using the model receptor biotin.

EXPERIMENTS

Dipalmitoylphosphatidylethanolamine-biotin (DPPE-biotin) was used in both procedures, lipopeptide-biotin and cholesterol-biotin were tested additionally for insertion into the intact lipid bilayer. The insertion method was optimized regarding incubation time, temperature and vesicle stability. The biotinylated vesicles of both functionalization methods were characterized with respect to their size, ζ-potential and binding functionality.

FINDINGS

Standard incorporation resulted in large variations in insertion-efficiency, high batch-to-batch differences, and an incorporation limit of 4 mol%. Best results were obtained through effortless insertion of the lipopeptide-biotin at room temperature. The concentration-controlled functionalization of liposomes (up to 10 mol%) could easily be monitored by the ζ-potential, resulted in reliable, quantitative binding to streptavidin and did not affect the analytical properties of the nanomaterial. This offers the possibility for a general modification strategy for lipid-based nanomaterials ideal for assay optimizations or multi-analyte detection.

Immunomodulatory Lipocomplex Functionalized with Photosensitizer-Embedded Cancer Cell Membrane Inhibits Tumor Growth and Metastasis

Liposomes are clinically used as drug carriers for cancer therapy; however, unwanted leakage of the encapsulated anticancer drug and poor tumor-targeting efficiency of liposomes may generate toxic side effects on healthy cells and lead to failure of tumor eradication. To overcome these limitations, we functionalized liposomes with a photosensitizer (KillerRed, KR)-embedded cancer cell membrane (CCM). A lipid adjuvant was also embedded in the lipocomplex to promote the anticancer immune response. KR proteins were expressed on CCM and did not leak from the lipocomplex. Owing to the homotypic affinity of the CCM for the source cancer cells, the lipocomplex exhibited a 3.3-fold higher cancer-targeting efficiency in vivo than a control liposome. The liposome functionalized with KR-embedded CCM and lipid adjuvant generated cytotoxic reactive oxygen species in photodynamic therapy and effectively induced anticancer immune responses, inhibiting primary tumor growth and lung metastasis in homotypic tumor-bearing mice. Taken together, the lipocomplex technology may improve liposome-based cancer therapy.

Paclitaxel prodrug based mixed micelles for tumor-targeted chemotherapy

Paclitaxel prodrug based mixed micelles with high drug loading and tumor targeting capacity for elevated chemotherapy.

Antioxidant nanomaterials in advanced diagnoses and treatments of ischemia reperfusion injuries

Organ ischemia with inadequate oxygen supply followed by reperfusion (which initiates a complex of inflammatory responses and oxidative stress) occurs in different clinical conditions and surgical procedures including stroke, myocardial infarction, limb ischemia, renal failure, organ transplantation, free-tissue-transfer, cardiopulmonary bypass, and vascular surgery. Even though pharmacological treatments protect against experimental ischemia reperfusion (I/R) injury, there has not been enough success in their application for patient benefits. The main hurdles in the treatment of I/R injury are the lack of diagnosis tools for understanding the complicated chains of I/R-induced signaling events, especially in the acute phase after ischemia, determining the affected regions of the tissue over time, and then, targeting and safe delivery of antioxidants, drugs, peptides, genes and cells to the areas requiring treatment. Besides the innate antioxidant and free radical scavenging properties, some nanoparticles also show higher flexibility in drug delivery and imaging. This review highlights three main approaches in nanoparticle-mediated targeting of I/R injury: nanoparticles (1) as antioxidants for reducing tissue oxidative stress, (2) for targeted delivery of therapeutic agents to the ischemic regions or cells, and (3) for imaging I/R injury at the molecular, cellular or tissue level and monitoring its evolution using contrasts induced by nanoparticles. These approaches can also be combined to realize so called theranostics for providing simultaneous diagnosis of ischemic regions and treatments by targeted delivery.

Hollow carbon nanospheres for targeted delivery of chemotherapeutics in breast cancer therapy

Functional hollow carbon nanospheres were prepared and antibody modified, which improved the targeted delivery of anti-tumor drug.