Study on the protection of dextran on erythrocytes during drug loading

RBCs as a Bioinspired Drug Delivery System for Co-delivery of Irinotecan and Nanoalumina Enhances Colorectal Cancer Therapy

Colorectal cancer (CRC) is a malignant epithelial tumor with high morbidity and mortality. In CRC treatment, irinotecan (CPT-11) as a chemotherapeutic drug is widely applied. However, its half-life is short, leading to large dosages and severe side effects. Red blood cells (RBCs) are biocompatible drug carriers with high capacity, avoiding premature drug degradation and achieving slow drug release. Nanoalumina (AN) is an emerging immune adjuvant that can enhance the immune response. Here, we used RBCs as carriers and absorbed AN to construct AN-CPT-11-RBCs. CPT-11 would induce tumor cell death, releasing much tumor antigen, while AN would activate immune cells to recognize newly released antigens and induce lymphocyte proliferation, enhancing the antitumor effect simultaneously. With loading amounts of 4 mg of CPT-11 and 3 mg of AN per 109 RBCs, AN-CPT-11-RBCs had similar properties to natural RBCs. In vivo, AN-CPT-11-RBCs could circulate for 9 days and stimulate the proliferation of lymphocytes in the spleen and tumor tissue, having a higher tumor growth inhibition rate of 74.01% and a lower frequency of administration. In conclusion, AN-CPT-11-RBCs attain the co-delivery of CPT-11 and AN for the synergistic treatment of CRC.

Cyclic RGD modified dextran-quercetin polymer micelles for targeted therapy of breast cancer

Quercetin is a natural flavonoid found in many plants which has various pharmacological activities including antitumor effect. However, the poor water solubility and bioavailability limit the potential benefits of quercetin for patients. Thus, modifying quercetin structure and developing actively targeted drug delivery systems are extremely important for tumor precision therapy. Herein, polymer-drug conjugates dextran-quercetin (D-Q) and cRGD-dextran (R-D) were synthesized by grafting quercetin and polypeptide cRGDfk (Arg-Gly-Asp-(D-Phe)-Lys) to dextran. Then cRGD-modified dextran-quercetin polymer micelles (R-D-Q) were constructed by self-assembling of D-Q and R-D. R-D-Q micelles possessed appropriate particle size (133.4 nm), nearly neutral potential (8.14 mV) and excellent drug-loading efficiency (13.1 %) and achieved higher cytotoxicity, apoptosis induction and penetration to human breast cancer MCF-7 cells than the micelles unmodified with cRGD, which were ascribed to cRGD-integrin mediated transcytosis. R-D-Q micelles effectively suppressed tumor growth in tumor-bearing mice by delivering more quercetin throughout the tumor tissue. And R-D-Q micelles could promote the apoptosis of tumor cells by activating p38 and JNK signal pathways and suppressing ERK signal pathway. In addition, R-D-Q micelles had no damage to normal tissues of mice at therapeutic dose. These results indicate promising prospects for R-D-Q micelles as an effective drug delivery system against tumor.

Highly effective strategy for isolation of mononuclear cells from frozen cord blood

BACKGROUND AIMS

Cord blood mononuclear cells (CBMCs) comprise a variety of single-nucleated cells found in the cord blood, mainly consisting of monocytes and lymphocytes. They also include a smaller proportion of other cell types, such as hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). CBMCs are vital for acquiring HSPCs, MSCs, and other immune cells, like natural killer cells. These cells are essential for supporting subsequent research and clinical applications. Although automated equipment for CBMC enrichment has shown promise, the high cost of these machines and the expense of disposable consumables limit their routine use. Furthermore, limited information is available on manual strategies for isolating CBMCs from cryopreserved cord blood. Therefore, we aimed to optimize the dilution buffer and refine the isolation procedure for CBMCs.

METHODS

We enhanced the CBMC recovery rate from cryopreserved cord blood using an optimized dilution buffer and a modified isolation procedure.

RESULTS

We achieved average recovery rates of 42.4 % and 54.3 % for CBMCs and CD34+ cells, respectively. Notably, all reagents used in the isolation procedure were of GMP-grade or pharmaceutical preparations, underscoring the potential clinical benefits of our strategy.

DISCUSSION

We devised an optimized protocol suitable for routine research and clinical applications for enhanced recovery of CBMCs from cryopreserved cord blood units using an optimized dilution buffer and a modified isolation procedure.

Intelligent berberine-loaded erythrocytes attenuated inflammatory cytokine productions in macrophages

Erythrocytes are impressive tools for drug delivery, especially to macrophages. Therefore, berberine was loaded into erythrocytes using both hypotonic pre-swelling and endocytosis methods to target macrophages. Physicochemical and kinetic parameters of the resulting carrier cells, such as drug loading/release kinetics, osmotic fragility, and hematological indices, were determined. Drug loading was optimized for the study using Taguchi experimental design and lab experiments. Loaded erythrocytes were targeted to macrophages using ZnCl2 and bis-sulfosuccinimidyl-suberate, and targeting was evaluated using flow cytometry and Wright-Giemsa staining. Differentiated macrophages were stimulated with lipopolysaccharide, and the inflammatory profiles of macrophages were evaluated using ELISA, western blotting, and real-time PCR. Findings indicated that the endocytosis method is preferred due to its low impact on the erythrocyte's structural integrity. Maximum loading achieved (1386.68 ± 22.43 μg/ml) at 1500 μg/ml berberine treatment at 37 °C for 2 h. Berberine successfully inhibited NF-κB translation in macrophages, and inflammatory response markers such as IL-1β, IL-8, IL-23, and TNF-α were decreased by approximately ninefold, sixfold, twofold, eightfold, and twofold, respectively, compared to the LPS-treated macrophages. It was concluded that berberine-loaded erythrocytes can effectively target macrophages and modulate the inflammatory response.

Progress of cell membrane-derived biomimetic nanovesicles for cancer phototherapy

In recent years, considerable attention has been given to phototherapy, including photothermal and photodynamic therapy to kill tumor cells by producing heat or reactive oxygen species (ROS). It has the high merits of noninvasiveness and limited drug resistance. To fully utilize this therapy, an extraordinary nanovehicle is required to target phototherapeutic agents in the tumor cells. Nanovesicles embody an ideal strategy for drug delivery applications. Cell membrane-derived biomimetic nanovesicles represent a developing type of nanocarrier. Combining this technique with cancer phototherapy could enable a novel strategy. Herein, efforts are made to describe a comprehensive overview of cell membrane-derived biomimetic nanovesicles for cancer phototherapy. The description in this review is mainly based on representative examples of exosome-derived biomimetic nanomedicine research, ranging from their comparison with traditional nanocarriers to extensive applications in cancer phototherapy. Additionally, the challenges and future prospectives for translating these for clinical application are discussed.

Advances in Targeting Drug Biological Carriers for Enhancing Tumor Therapy Efficacy

Chemotherapy drugs continue to be the main component of oncology treatment research and have been proven to be the main treatment modality in tumor therapy. However, the poor delivery efficiency of cancer therapeutic drugs and their potential off-target toxicity significantly limit their effectiveness and extensive application. The recent integration of biological carriers and functional agents is expected to camouflage synthetic biomimetic nanoparticles for targeted delivery. The promising candidates, including but not limited to red blood cells and their membranes, platelets, tumor cell membrane, bacteria, immune cell membrane, and hybrid membrane are typical representatives of biological carriers because of their excellent biocompatibility and biodegradability. Biological carriers are widely used to deliver chemotherapy drugs to improve the effectiveness of drug delivery and therapeutic efficacy in vivo, and tremendous progress is made in this field. This review summarizes recent developments in biological vectors as targeted drug delivery systems based on microenvironmental stimuli-responsive release, thus highlighting the potential applications of target drug biological carriers. The review also discusses the possibility of clinical translation, as well as the exploitation trend of these target drug biological carriers.

Red blood cells: a potential delivery system

Red blood cells (RBCs) are the most abundant cells in the body, possessing unique biological and physical properties. RBCs have demonstrated outstanding potential as delivery vehicles due to their low immunogenicity, long-circulating cycle, and immune characteristics, exhibiting delivery abilities. There have been several developments in understanding the delivery system of RBCs and their derivatives, and they have been applied in various aspects of biomedicine. This article compared the various physiological and physical characteristics of RBCs, analyzed their potential advantages in delivery systems, and summarized their existing practices in biomedicine.

Glutaraldehyde modified red blood cells delivering artesunate to the liver as a dual therapeutic and prophylactic antimalaria strategy

Malaria can spread quickly in the population and develop rapidly. Patients with malaria usually die due to lack of timely and effective treatment. Artesunate (AS) is a highly effective and low-toxicity antimalarial drug, but its short half-life in the blood makes it difficult to control the malaria infection completely. Red blood cells (RBCs) have great biodegradability and can be employed to encapsulate various drugs. In this work, we employed RBCs as carriers to encapsulate AS and modified them with glutaraldehyde to construct an intelligent response drug delivery system (G-AS-RBCs) targeting the liver for antimalaria therapeutic and prophylactic activity. The G-AS-RBCs had a drug loading amount of 6.56 ± 0.14 mg 10-8 cells, suggesting excellent biocompatibility. G-AS-RBCs exhibited strong liver targeting efforts and can be maintained in the mice for at least 9 days, showing the potential for malaria prevention. The enrichment of AS in the liver was enhanced because of the natural liver targeting of erythrocytes and the enhancement of liver targeting by glutaraldehyde treatment. Furthermore, AS entrapped into RBCs also showed improved slow-release characteristics and achieved a better effect of inhibiting or killing the malaria parasite than free drugs. Therefore, this RBC-based strategy is expected to realize the prevention and treatment of malaria and has good application prospects.

Cellular Drug Delivery System for Disease Treatment

The application of variable novel drug delivery system has shown a flowering trend in recent years. Among them, the cell-based drug delivery system (DDS) utilizes the unique physiological function of cells to deliver drugs to the lesion area, which is the most complex and intelligent DDS at present. Compared with the traditional DDS, the cell-based DDS has the potential of prolonged circulation in body. Cellular DDS is expected to be the best carrier to realize multifunctional drug delivery. This paper introduces and analyzes common cellular DDSs such as blood cells, immune cells, stem cells, tumor cells and bacteria as well as relevant research examples in recent years. We hope that this review can provide a reference for future research on cell vectors and promote the innovative development and clinical transformation of cell-based DDS.

Membrane-Coated Biomimetic Nanoparticles: A State-of-the-Art Multifunctional Weapon for Tumor Immunotherapy

The advent of immunotherapy, which improves the immune system’s ability to attack and eliminate tumors, has brought new hope for tumor treatment. However, immunotherapy regimens have seen satisfactory results in only some patients. The development of nanotechnology has remarkably improved the effectiveness of tumor immunotherapy, but its application is limited by its passive immune clearance, poor biocompatibility, systemic immunotoxicity, etc. Therefore, membrane-coated biomimetic nanoparticles have been developed by functional, targeting, and biocompatible cell membrane coating technology. Membrane-coated nanoparticles have the advantages of homologous targeting, prolonged circulation, and the avoidance of immune responses, thus remarkably improving the therapeutic efficacy of tumor immunotherapy. Herein, this review explores the recent advances and future perspectives of cell membrane-coated nanoparticles for tumor immunotherapy.

Cyclic arginine-glycine-aspartic acid-modified red blood cells for drug delivery: Synthesis and in vitro evaluation

Red blood cells (RBCs) are an excellent choice for cell preparation research because of their biocompatibility, high drug loading, and long half-life. In this study, doxorubicin (DOX) was encapsulated with RBCs as the carrier. The biotin-avidin system binding principle was used to modify biotinylated cyclic arginine-glycine-aspartic acid (cRGD) onto RBC surfaces for accurate targeting, high drug loading, and sustained drug release. The RBC drug delivery system (DDS) was characterized, and the concentration of surface sulfur in the energy spectrum was 6.330%. The physical and chemical properties of RBC DDS were as follows: drug content, 0.857 mg/mL; particle size, 3339 nm; potential value, -12.5 mV; and cumulative release rate, 81.35%. There was no significant change in RBC morphology for up to seven days. The results of the targeting and cytotoxicity studies of RBC DDS showed that many RBCs covered the surfaces of U251 cells, and the fluorescence intensity was higher than that of MCF-7 cells. The IC50 value of unmodified drug-loaded RBCs was 2.5 times higher than that of targeted modified drug-loaded RBCs, indicating that the targeting of cancer cells produced satisfactory inhibition. This study confirms that the RBC DDS has the characteristics of accurate targeting, high drug loading, and slow drug release, which increases its likelihood of becoming a clinical cancer treatment in the future.

Recent Advances in Gelatin-Based Nanomedicine for Targeted Delivery of Anti-Cancer Drugs

Nanoparticles based on natural polymers are utilized for the development of a wide range of drug delivery systems (DDS) in the current era. Gelatin-based nanoparticles, for example, are a remarkable cancer therapy with high efficacy and specificity. This paper reviews the recent advancements in gelatin-based nanomedicine for use in cancer therapeutics. Due to the characteristics features of gelatin, such as biocompatibility, biodegradability, stability, and good surface properties, these nanoparticles provide high therapeutic potency in cancer nanomedicine. The surface of gelatin can be modified in a number of ways using various ligands to explore the platform for the development of a more novel DDS. Various methods are available for the preparation of gelatin nanomedicine discussed in this review. In addition, various cross-linkers to stabilized nanocarriers and stimuli base gelatin nanoparticles are reviewed. Furthermore, recent advances and research in gelatin-based nanomedicine are discussed. Also, some drawbacks and challenges are evaluated. In general, this paper paves the pathway to identify the details about the gelatin-based DDS for cancer therapy.

Clinical progress and advanced research of red blood cells based drug delivery system

Red blood cells (RBCs) are biocompatible carriers that can be employed to deliver different bioactive substances. In the past few decades, many strategies have been developed to encapsulate or attach drugs to RBCs. Osmotic-based encapsulation methods have been industrialized recently, and some encapsulated RBC formulations have reached the clinical stage for treating tumors and neurological diseases. Inspired by the intrinsic properties of intact RBCs, some advanced delivery strategies have also been proposed. These delivery systems combine RBCs with other novel systems to further exploit and expand the application of RBCs. This review summarizes the clinical progress of drugs encapsulated into intact RBCs, focusing on the loading and clinical trials. It also introduces the latest advanced research based on developing prospects and limitations of intact RBCs drug delivery system (DDS), hoping to provide a reference for related research fields and further application potential of intact RBCs based drug delivery system.

Bacteria and Archaea: A new era of cancer therapy

Cancer is one of the most important mortality in the world. The major drawbacks of chemotherapy are the poor absorption of drugs into tumor tissues and development of resistance against anti-cancer agents. To overcome these limitations, the use of microorganisms has been extensively considered in the treatment of cancer. Microorganisms (bacteria/Archaea) secrete different bioactive compounds that can efficiently inhibit cancer cells growth. Biological nanocarriers derived from microorganisms including outer membrane vesicles (OMVs), bacterial ghosts (BGs) and archaeosomes have also been considered as drug delivery systems. Conjugation of drug loaded nanocarriers to bacteria strongly kills the cancer cells after internalization through the bacteria. Merging of microbiology and nanotechnology may provide versatile microbial nano-hybrids for promising treatment of cancer. This strategy causes more amount of drug to enter into cancer cells. In this review, we present evidence that microorganism, their derivatives as well as their intervention with nanotechnology can be a powerful vehicle for eradication cancer.

Recent progress on nanomedicine-induced ferroptosis for cancer therapy

The current treatment strategies for cancer therapy have posed many problems in achieving high efficacy. Therefore, an urgent step is needed to develop innovative therapies that can win beyond satisfactory results against tumor. Ferroptosis that is a kind of non-apoptotic based programmed cell death has played a crucial role in eradicating tumors by reactive oxygen species and iron-dependent pathways. Research shows a remarkable potential of ferroptosis in eliminating aggressive malignancies resistant to traditional therapies. The combination of nanomedicine and ferroptosis has revealed a close relationship for the treatment of various cancer types with high efficacy. This review introduces the basics of nanomedicine-based ferroptosis first to emphasize the feasibility and properties of ferroptosis in cancer therapy. Then, the current research on the applications of nanomedicine for the ferroptosis-based anticancer therapy is highlighted. Finally, conclusions and future research directions in perspective of various challenges in developing nanomedicine-based ferroptosis into clinical therapeutics are discussed.

Recent Advances in Cell Membrane-Derived Biomimetic Nanotechnology for Cancer Immunotherapy

Immunotherapy will significantly impact the standard of care in cancer treatment. Recent advances in nanotechnology can improve the efficacy of cancer immunotherapy. However, concerns regarding efficiency of cancer nanomedicine, complex tumor microenvironment, patient heterogeneity, and systemic immunotoxicity drive interest in more novel approaches to be developed. For this purpose, biomimetic nanoparticles are developed to make innovative changes in the delivery and biodistribution of immunotherapeutics. Biomimetic nanoparticles have several advantages that can advance the clinical efficacy of cancer immunotherapy. Thus there is a greater push toward the utilization of biomimetic nanotechnology for developing effective cancer immunotherapeutics that demonstrate increased specificity and potency. The recent works and state-of-the-art strategies for anti-tumor immunotherapeutics are highlighted here, and particular emphasis has been given to the applications of cell-derived biomimetic nanotechnology for cancer immunotherapy.

Preparation of dextran-casein phosphopeptide conjugates, evaluation of its calcium binding capacity and digestion in vitro

In order to construct a novel and efficient calcium delivery system, a dextran- casein phosphopeptide (CPP) conjugates as calcium carrier was prepared by Maillard reaction of CPP and dextran. The preparation of the conjugates, construction of calcium delivery system and digestion in vitro were studied. The grafting rate of conjugates, which was confirmed by migration and intensity changes in the characteristic peaks using ultraviolet-visible and Fourier transform infrared spectroscopy, reached 48.88%. The microscopy showed CPP was coated with dextran, the conjugates with a kind of "shell-core" structure had excellent stability. Compared with CPP, the chelating rate of conjugates increased from 6.0% to 13.87%, and the calcium retention rate improved from 1.09% to 7.90% in vitro digestion. The calcium binding capacity and effect of controlled release of the conjugates were superior to those of CPP. Therefore, the conjugates could be used as an effective carrier for new calcium supplements.

A novel dextranase gene from the marine bacterium Bacillus aquimaris S5 and its expression and characteristics

Dextranase specifically hydrolyzes dextran and is used to produce functional isomalto-saccharide prebiotics. Moreover, dextranase is used as an additive in mouthwash to remove dental plaque. We cloned and expressed the dextranase gene of the marine bacterium Bacillus aquimaris S5. The length of the BaDex gene was 1788 bp, encoding 573 amino acids. Using bioinformatics to predict and analyze the amino acid sequence of BaDex, we found the isoelectric point and instability coefficient to be 4.55 and 29.22, respectively. The average hydrophilicity (GRAVY) was -0.662. The secondary structure of BaDex consisted of 145 alpha helices, accounting for 25.31% of the protein; 126 extended strands, accounting for 21.99%; and 282 random coils, accounting for 49.21%. The 3D structure of the BaDex protein was predicted and simulated using SWISS-MODEL, and BaDex was classified as a Glycoside Hydrolase Family 66 protein. The optimal temperature and pH for BaDex activity were 40°C and 6.0, respectively. The hydrolysates had excellent antioxidant activity, and 8 U/mL of BaDex could remove 80% of dental plaque in MBRC experiment. This recombinant protein thus has great promise for applications in the food and pharmaceutical industries.