Harnessing tetrahedral framework nucleic acids for enhanced delivery of microRNA-149-3p: A new frontier in oral squamous cell carcinoma therapy.

Oral squamous cell carcinoma (OSCC), a type of malignant tumour that primarily occurs in the oral mucosa, has drawn considerable attention owing to its aggressive growth and potentially high metastatic rate. Surgical resection is the primary treatment method for OSCC and is typically combined with radiation therapy and chemotherapy. microRNA-149-3p (miR-149) is a negative regulator of the Pi3k/Akt pathway and can effectively inhibit the proliferation of tumour cells. However, the application of miR-149 is limited owing to its relatively low efficiency of cellular uptake and poor stability when used alone. To overcome these challenges, this study adopted a novel nucleic acid nanostructured material, tetrahedral framework nucleic acids (tFNAs). The use of tFNAs as carriers to assemble the T-miR-149 complex reduced the expression of Pi3k and Akt involved in tumorigenesis and alterations in proteins related to cell apoptosis. The results indicated that the bionic drug delivery system has an effective tumour suppressive effect on OSCC in mice, revealing its potential clinical value in the treatment of OSCC.

Tetrahedral framework nucleic acids/hyaluronic acid-methacrylic anhydride hybrid hydrogel with antimicrobial and anti-inflammatory properties for infected wound healing.

Bacterial resistance and excessive inflammation are common issues that hinder wound healing. Antimicrobial peptides (AMPs) offer a promising and versatile antibacterial option compared to traditional antibiotics, with additional anti-inflammatory properties. However, the applications of AMPs are limited by their antimicrobial effects and stability against bacterial degradation. TFNAs are regarded as a promising drug delivery platform that could enhance the antibacterial properties and stability of nanodrugs. Therefore, in this study, a composite hydrogel (HAMA/t-GL13K) was prepared via the photocross-linking method, in which tFNAs carry GL13K. The hydrogel was injectable, biocompatible, and could be instantly photocured. It exhibited broad-spectrum antibacterial and anti-inflammatory properties by inhibiting the expression of inflammatory factors and scavenging ROS. Thereby, the hydrogel inhibited bacterial infection, shortened the wound healing time of skin defects in infected skin full-thickness defect wound models and reduced scarring. The constructed HAMA/tFNA-AMPs hydrogels exhibit the potential for clinical use in treating microbial infections and promoting wound healing.

Transcutaneous Immunotherapy for RNAi: A Cascade-Responsive Decomposable Nanocomplex Based on Polyphenol-Mediated Framework Nucleic Acid in Psoriasis.

Skin is the first barrier against external threats, and skin immune dysfunction leads to multiple diseases. Psoriasis is an inflammatory, chronic, common, immune-related skin disease that affects more than 125 million people worldwide. RNA interference (RNAi) therapy is superior to traditional therapies, but rapid degradation and poor cell uptake are the greatest obstacles to its clinical transformation. The transdermal delivery of siRNA and controllable assembly/disassembly of nanodrug delivery systems can maximize the therapeutic effect. Tetrahedral framework nucleic acid (tFNA) is undoubtedly the best carrier for the transdermal transport of genes due to its excellent noninvasive transdermal effect and editability. The authors combine acid-responsive tannic acid (TA), RNase H-responsive sequences, siRNA, and tFNA into a novel transdermal RNAi drug with controllable assembly and disassembly: STT. STT has heightened resistance to enzyme, serum, and lysosomal degradation, and its size is similar to that of tFNA, enabling easy transdermal transport. After transdermal administration, STT can specifically silence nuclear factor kappa-B (NF-κB) p65, thereby maintaining the stability of the skin's microenvironment and reshaping normal skin immune defense. This work demonstrates the advantages of STT in RNAi therapy and the potential for future treatment of skin-related diseases.

Application and prospects of nucleic acid nanomaterials in tumor therapy.

Cancer poses a great threat to human life, and current cancer treatments, such as radiotherapy, chemotherapy, and surgery, have significant side effects and limitations that hinder their application. Nucleic acid nanomaterials have specific spatial configurations and can be used as nanocarriers to deliver different therapeutic drugs, thereby enabling various biomedical applications, such as biosensors and cancer therapy. In recent decades, a variety of DNA nanostructures have been synthesized, and they have demonstrated remarkable potential in cancer therapy related applications, such as DNA origami structures, tetrahedral framework nucleic acids, and dynamic DNA nanostructures. Importantly, more attention is also being paid to RNA nanostructures, which play an important role in gene therapy. Therefore, this review introduces the developmental history of nucleic acid nanotechnology, summarizes the applications of DNA and RNA nanostructures for tumor treatment, and discusses the development opportunities for nucleic acid nanomaterials in the future.

Tetrahedral-Framework Nucleic Acid Loaded with MicroRNA-155 Enhances Immunocompetence in Cyclophosphamide-Induced Immunosuppressed Mice by Modulating Dendritic Cells and Macrophages.

Nanomaterials are often used as immunomodulators because they can be tailored by a controllable process. In this work, a complex based on a tetrahedral framework nucleic acid delivery system and MicroRNA-155, known as T-155, is synthesized for the modulation of immunosuppression. In vivo, T-155 ameliorated spleen and thymus damage and hematopoiesis suppression in cyclophosphamide-induced immunosuppressed mice by promoting T-cell proliferation to resist oxidative stress. In vitro, T-155 induced immature dendritic cells (DCs) to differentiate into mature DCs by the ERK1/2 pathway and converted M0 macrophages (Mφ) into the M1 type by the NF-κB pathway to enhance the surveillance capabilities of antigen-presenting cells. The experimental results suggest that T-155 has therapeutic potential as an immunomodulator for immunosuppression.

Antifibrotic Effects of Tetrahedral Framework Nucleic Acids by Inhibiting Macrophage Polarization and Macrophage-Myofibroblast Transition in Bladder Remodeling.

Bladder outlet obstruction (BOO) is a prevalent condition arising from urethral stricture, posterior urethral valves, and benign prostatic hyperplasia. Long-term obstruction can lead to bladder remodeling, which is characterized by inflammatory cell infiltration, detrusor hypertrophy, and fibrosis. Until now, there are no efficacious therapeutic options for BOO-induced remodeling. Tetrahedral framework nucleic acids (tFNAs) are a type of novel 3D DNA nanomaterials that possess excellent antifibrotic effects. Here, to determine the treatment effects of tFNAs on BOO-induced remodeling is aimed. Four single-strand DNAs are self-assembled to form tetrahedral framework DNA nanostructures, and the antifibrotic effects of tFNAs are investigated in an in vivo BOO animal model and an in vitro transforming growth factor beta1 (TGF-ß1)-induced fibrosis model. The results demonstrated that tFNAs could ameliorate BOO-induced bladder fibrosis and dysfunction by inhibiting M2 macrophage polarization and the macrophage-myofibroblast transition (MMT) process. Furthermore, tFNAs regulate M2 polarization and the MMT process by deactivating the signal transducer and activator of transcription (Stat) and TGF-ß1/small mothers against decapentaplegic (Smad) pathways, respectively. This is the first study to reveal that tFNAs might be a promising nanomaterial for the treatment of BOO-induced remodeling.

Myelosuppression Alleviation and Hematopoietic Regeneration by Tetrahedral-Framework Nucleic-Acid Nanostructures Functionalized with Osteogenic Growth Peptide.

As major complications of chemoradiotherapy, myelosuppression and hematopoietic-system damage severely affect immunologic function and can delay or even terminate treatment for cancer patients. Although several specific cytokines have been used for hematopoiesis recovery, their effect is limited, and they may increase the risk of tumor recurrence. In this study, osteogenic growth peptide functionalized tetrahedral framework nucleic-acid nanostructures (OGP-tFNAs) are prepared; they combine the positive hematopoiesis stimulating effect of OGP and the drug carrying function of tFNAs. The potential of OGP-tFNAs for hematopoietic stimulation and microenvironment regulation is investigated. It is shown that OGP-tFNAs can protect bone marrow stromal cells from 5-fluorouracil (5-FU)-induced DNA damage and apoptosis. OGP-tFNAs pretreatment activates the extracellularly regulated protein kinase signal and downregulates apoptosis-related proteins. OGP-tFNAs also alleviate the chemotherapy-induced inhibition of hematopoiesis-related cytokine expression, which is crucial for hematopoiesis reconstitution. In conclusion, OGP-tFNAs can protect hematopoietic cells and their microenvironment from chemotherapy-induced injuries and myelosuppression, while promoting hematopoiesis regeneration.

Tetrahedral framework nucleic acid carrying angiogenic peptide prevents bisphosphonate-related osteonecrosis of the jaw by promoting angiogenesis.

The significant clinical feature of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is the exposure of the necrotic jaw. Other clinical manifestations include jaw pain, swelling, abscess, and skin fistula, which seriously affect the patients' life, and there is no radical cure. Thus, new methods need to be found to prevent the occurrence of BRONJ. Here, a novel nanoparticle, tFNA-KLT, was successfully synthesized by us, in which the nanoparticle tetrahedral framework nucleic acid (tFNA) was used for carrying angiogenic peptide, KLT, and then further enhanced angiogenesis. TFNA-KLT possessed the same characteristics as tFNA, such as simple synthesis, stable structure, and good biocompatibility. Meanwhile, tFNA enhanced the stability of KLT and carried more KLT to interact with endothelial cells. First, it was confirmed that tFNA-KLT had the superior angiogenic ability to tFNA and KLT both in vitro and in vivo. Then we apply tFNA-KLT to the prevention of BRONJ. The results showed that tFNA-KLT can effectively prevent the occurrence of BRONJ by accelerating angiogenesis. In summary, the prepared novel nanoparticle, tFNA-KLT, was firstly synthesized by us. It was also firstly confirmed by us that tFNA-KLT significantly enhanced angiogenesis and can effectively prevent the occurrence of BRONJ by accelerating angiogenesis, thus providing a new avenue for the prevention of BRONJ and a new choice for therapeutic angiogenesis.

Anti-inflammatory activity of curcumin-loaded tetrahedral framework nucleic acids on acute gouty arthritis.

Gouty arthritis is a very familiar inflammatory arthritis. Controlling inflammation is the key to preventing gouty arthritis. However, colchicine, the most highly represented drug used in clinical practice, has strict contraindications owing to some severe side effects. Curcumin (Cur), a natural anti-inflammatory drug, has demonstrated good safety and efficacy. However, the rapid degradation, poor aqueous solubility, and low bioavailability of Cur limit its therapeutic effect. To strengthen the effectiveness and bioavailability of Cur. Cur loaded tetrahedral framework nucleic acids (Cur-TFNAs) were synthesized to deliver Cur. Compared with free Cur, Cur-TFNAs exhibit a preferable drug stability, good biocompatibility (CCK-8 assay), ease of uptake (immunofluorescence), and higher tissue utilization (in vivo biodistribution). Most importantly, Cur-TFNAs present better anti-inflammatory effect than free Cur both in vivo and in vitro experiments through the determination of inflammation-related cytokines expression. Therefore, we believe that Cur-TFNAs have great prospects for the prevention of gout and similar inflammatory diseases.

Biological Effect of Differently Sized Tetrahedral Framework Nucleic Acids: Endocytosis, Proliferation, Migration, and Biodistribution.

With the advent of nanotechnology, DNA nanostructures have been widely applied in various fields, particularly biology and biomedicine. Tetrahedral framework nucleic acids (TFNAs), a novel type of DNA nanomaterial, have attracted considerable attention due to their simple synthesis, high accessibility, structural stability, and versatility. However, to date, the interaction of differently sized TFNAs with living systems and their ability to be endocytosed and biodistributed in mouse is still not fully understood. To screen for the optimal TFNA size and structures, TFNA endocytosis, proliferation, and migration were tested in adipose stem cells (ASCs). We found that the internalization of differently sized TFNAs in ASCs was remarkably different. Although all TFNAs could enter ASCs, T21 had the best membrane-penetrating ability. After exposure of ASCs to TFNAs of different sizes, the proliferation and migration of cells were enhanced, especially with T21. Importantly, T21 could access the brain and accumulate over time. This study improves our understanding of the influence of TFNA size on the biological behavior of ASCs, which will help in choosing optimal TFNA size for biomedical applications.

Tetrahedral Framework Nucleic Acids Reverse New-Onset Type 1 Diabetes.

Type 1 diabetes (T1D) is caused by breakdowns of central and peripheral immune tolerance and destructions of insulin-producing ß-cells. Conventional insulin injection cannot cure the disease. Regulatory immune cells, including regulatory T-cells (Tregs) and regulatory B-cells (Bregs), play critical roles in immune tolerance. Inducing regulatory immune cells to halt the progress of T1D and restore immune tolerance is the promising approach in T1D immunotherapy. Here, tetrahedral framework nucleic acids (tFNAs) were utilized to treat T1D in non-obese diabetic (NOD) mice. 250 nM tFNA treatment was adopted in the experiment to reverse hyperglycemia and protect insulin-secreting ß-cells in diabetic NOD mice. In addition, 250 nM tFNA treatment could induce Tregs and Bregs and suppress helper T (Th)-cells in the pancreas. In the pancreas, cytokines, as a significant signal during CD4+ T-cell differentiation, directly direct the differentiation programs. Apart from cytokines directing the differentiation of T-cells, the signal transducer and activator of transcription (STAT) signal is strongly associated with T-cell differentiation and T1D progression. We demonstrated tFNA treatment inducing regulatory immune cells probably by increasing TGF-ß levels and the STAT signal. To sum up, 250 nM tFNA treatment could protect the diabetic NOD mice from hyperglycemia and preserve the functions of ß-cells by restoring peripheral immune tolerance. The possible mechanism of inducing immune tolerance was related to the STAT signal and cytokine changes in the pancreas. Moreover, immunoregulation capabilities of tFNAs were demonstrated in the experiment, which set the foundation of tFNAs participating in further antigen-specific immunotherapies.

Tetrahedral framework nucleic acids facilitate neurorestoration of facial nerves by activating the NGF/PI3K/AKT pathway.

The facial nerve is a crucial nerve in the maxillofacial region and is vulnerable to damage. As a consequence of the complications during nerve restoration, existing remedies have certain limitations, thus the treatment of facial nerve injury is always a perplexing task for people. Regulation of Schwann cells is always the breakpoint of neurorestoration since Schwann cells count a great deal in injured nerve repair. In this study, we presented proof that tetrahedral framework nucleic acids (tFNAs), a kind of nucleic acid nanomaterial, were capable of regulating the neurorestorative pathway NGF/PI3 K/AKT, resulting in the activation of a series of cell behaviors related to injured nerve restoration such as proliferation and migration. In vivo experiments also proved that tFNAs enhanced the expressions of axon and myelin marker proteins, impelled histological recovery, promoted the efficient restoration of nerve conduction and muscle movement. Additionally, tFNAs possessed excellent biocompatibility and superior endocytosis ability. Thus, there is good potential for tFNAs to be applied in the therapy of facial nerve injury or even peripheral nerve injury.

Tetrahedral Framework Nucleic Acids Reestablish Immune Tolerance and Restore Saliva Secretion in a Sjögren's Syndrome Mouse Model.

As one of the most frequent autoimmune diseases, Sjogren's syndrome (SS) is characterized by overactive lymphocytic infiltration in the exocrine glands, with ensuing dry mouth and dry eyes. Unfortunately, so far, there are no appropriate therapies without causing overall immunosuppression. Tetrahedral framework nucleic acids (tFNAs) were regarded as promising nanoscale materials whose immunomodulatory capabilities have already been verified. Herein, we reveal, for the first time, that tFNAs were utilized to treat SS in female nonobese diabetic (NOD) mice, the animal model used for SS. We proved a 250 nM tFNA treatment was successful in suppressing inflammation and stimulating saliva secretion in NOD mice. Specialised proteins for the secretory function and structure of acinar cells in submandibular glands (SMGs) were restored. It has been the permanent goal for SS treatment to establish immune tolerance and stop disease development. Surprisingly, tFNA treatment guided T cells toward regulatory T cells (Tregs), while suppressing T helper (Th) cell responses. Th cells include Th1, Th17, and follicular helper T (Tfh) cells. Tregs are highly significant in immune tolerance. Inducing Tregs is a promising approach to reestablish immune tolerance. Comparable results were also observed in B cell responses. Reductions in the percentage of germinal center (GC) B cells and plasma cells were detected, and a marked increase in the percentage of regulatory B cells (Bregs) was also noticed. The mechanisms of inducing Tregs may associated with cytokine changes. Changes of T cell subsets, especially changes of Tfh, may influence the differentiation of B cells accordingly. Collectively, our results demonstrated the immunomodulatory capacities of tFNAs once again, which may provide a novel, safe, and effective option for the treatment of SS and other autoimmune diseases.

Tetrahedral Framework Nucleic Acids Ameliorate Insulin Resistance in Type 2 Diabetes Mellitus via the PI3K/Akt Pathway.

Insulin resistance (IR) is one of the essential conditions in the development of type 2 diabetes mellitus (T2DM). IR occurs in hepatic cells when the insulin receptor substrate-1 (IRS-1)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway is downregulated; thus, activating this pathway can significantly improve insulin sensitivity and ameliorate T2DM. Tetrahedral framework nucleic acids (tFNAs), a DNA nanomaterial, are synthesized from four single-stranded DNA molecules. tFNAs possess excellent biocompatibility and good water solubility and stability. tFNAs can promote cell proliferation, cell autophagy, wound healing, and nerve regeneration by activating the PI3K/Akt pathway. Herein, we explore the effects and underlying mechanisms of tFNAs on IR. The results displayed that tFNAs could increase glucose uptake and ameliorate IR by activating the IRS-1/PI3K/Akt pathway in glucosamine (GlcN)-stimulated HepG2 cells. By employing a PI3K inhibitor, we confirmed that tFNAs reduce IR through the PI3K/Akt pathway. Moreover, tFNAs can promote hepatic cell proliferation and inhibit GlcN-induced cell apoptosis. In a T2DM mouse model, tFNAs reduce blood glucose levels and ameliorate hepatic IR via the PI3K/Akt pathway. Taken together, tFNAs can improve hepatic IR and alleviate T2DM through the PI3K/Akt pathway, making contribution to the potential application of tFNAs in T2DM.

Aptamer-mediated synthesis of multifunctional nano-hydroxyapatite for active tumour bioimaging and treatment.

OBJECTIVES: The nano-hydroxyapatite (nHAp) is widely used to develop imaging probes and drug carriers due to its excellent bioactivity and biocompatibility. However, traditional methods usually need cumbersome and stringent conditions such as high temperature and post-modification to prepare the functionalized nHAp, which do not benefit the particles to enter cells due to the increased particle size. Herein, a biomimetic synthesis strategy was explored to achieve the AS1411-targeted tumour dual-model bioimaging using DNA aptamer AS1411 as a template. Then, the imaging properties and the biocompatibility of the synthesized AS-nFAp:Gd/Tb were further investigated. MATERIALS AND METHODS: The AS-nFAp:Gd/Tb was prepared under mild conditions through a one-pot procedure with AS1411 as a template. Besides, the anticancer drug DOX was loaded to AS-nFAp:Gd/Tb so as to achieve the establishment of a multifunctional nano-probe that integrated the tumour diagnosis and treatment. The AS-nFAp:Gd/Tb was characterized by transmission electron microscopy (TEM), energy disperse X-ray Spectroscopy (EDS) mapping, X-ray photoelectron spectroscopy (XPS) spectrum, X-ray diffraction (XRD), fourier-transformed infrared (FTIR) spectroscopy, capillary electrophoresis analyses, zeta potential and particle sizes. The in vitro magnetic resonance imaging (MRI) and fluorescence imaging were performed on an MRI system and a confocal laser scanning microscope, respectively. The potential of the prepared multifunctional nHAp for a targeted tumour therapy was investigated by a CCK-8 kit. And the animal experiments were conducted on the basis of the guidelines approved by the Animal Care and Use Committee of Sichuan University, China. RESULTS: In the presence of AS1411, the as-prepared AS-nFAp:Gd/Tb presented a needle-like morphology with good monodispersity and improved imaging performance. Furthermore, due to the specific binding between AS1411 and nucleolin up-expressed in cancer cells, the AS-nFAp:Gd/Tb possessed excellent AS1411-targeted fluorescence and MRI imaging properties. Moreover, after loading chemotherapy drug DOX, in vitro and in vivo studies showed that DOX@AS-nFAp:Gd/Tb could effectively deliver DOX to tumour tissues and exert a highly effective tumour inhibition without systemic toxicity compared with pure DOX. CONCLUSIONS: The results indicated that the prepared multifunctional nHAp synthesized by a novel biomimetic strategy had outstanding capabilities of recognition and treatment for the tumour and had good biocompatibility; hence, it might have a potential clinical application in the future.

Tetrahedral Framework Nucleic Acid-Based Delivery of Resveratrol Alleviates Insulin Resistance: From Innate to Adaptive Immunity.

Obesity-induced insulin resistance is the hallmark of metabolic syndrome, and chronic, low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells. Current therapeutic approaches lack efficacy and immunomodulatory capacity. Thus, a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance. Here, we synthesized a tetrahedral framework nucleic acid (tFNA) nanoparticle that carried resveratrol (RSV) to inhibit tissue inflammation and improve insulin sensitivity in obese mice. The prepared nanoparticles, namely tFNAs-RSV, possessed the characteristics of simple synthesis, stable properties, good water solubility, and superior biocompatibility. The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy. In high-fat diet (HFD)-fed mice, the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status. tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages. As for adaptive immunity, the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg, leading to the alleviation of insulin resistance. Furthermore, this study is the first to demonstrate that tFNAs, a nucleic acid material, possess immunomodulatory capacity. Collectively, our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice, suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.

Angiogenic Aptamer-Modified Tetrahedral Framework Nucleic Acid Promotes Angiogenesis In Vitro and In Vivo.

In a search for a solution to large-area soft and hard tissue defects, whether or not tissue regeneration or tissue-substitutes transplantation is used, the problems with angiogenesis need to be solved urgently. Thus, a new and efficient proangiogenic approach is needed. Nanoengineering systems have been considered one of the most promising approaches. In this study, we modify the tetrahedral framework nucleic acid (tFNA) for the first time with two different angiogenic DNA aptamers to form aptamer-tFNA nanostructures, tFNA-Apt02 and tFNA-AptVEGF, and the effects of them on angiogenesis both in vitro and in vivo are investigated. We develop new nanomaterials for enhancing angiogenesis to solve the problem of tissue engineering vascularization and ischemic diseases. The results of our study confirm that tFNA-Apt02 and tFNA-AptVEGF has a stronger ability to accelerate endothelial cell proliferation and migration, tubule formation, spheroid sprouting, and angiogenesis in vivo. We first demonstrate that the engineered novel tFNA-Apt02 and tFNA-AptVEGF have promoting effects on angiogenesis both in vitro and in vivo and provide a theoretical basis and opportunity for their application in tissues engineering vascularization and ischemic diseases.

Tetrahedral Framework Nucleic Acids Induce Immune Tolerance and Prevent the Onset of Type 1 Diabetes.

A failure in immune tolerance leads to autoimmune destruction of insulin-producing ß-cells, leading to type 1 diabetes (T1D). Inhibiting autoreactive T cells and inducing regulatory T cells (Tregs) to re-establish immune tolerance are promising approaches to prevent the onset of T1D. Here, we investigated the ability of tetrahedral framework nucleic acids (tFNAs) to induce immune tolerance and prevent T1D in nonobese diabetic (NOD) mice. In prediabetic NOD mice, tFNAs treatment led to maintenance of normoglycemia and reduced incidence of diabetes. Moreover, the tFNAs (250 nM) treatment preserved the mass and function of ß-cells, increased the frequency of Tregs, and suppressed autoreactive T cells, leading to immune tolerance. Collectively, our results demonstrate that tFNAs treatment aids glycemic control, provides ß-cell protection, and prevents the onset of T1D in NOD mice by immunomodulation. These results highlight the potential of tFNAs for the prevention of autoimmune T1D.

Tetrahedral DNA nanostructure improves transport efficiency and anti-fungal effect of histatin 5 against Candida albicans.

OBJECTIVES: Anti-microbial peptides (AMPs) have been comprehensively investigated as a novel alternative to traditional antibiotics against microorganisms. Meanwhile, Tetrahedral DNA nanostructures (TDNs) have gained attention in the field of biomedicine for their premium biological effects and transportation efficiency as delivery vehicles. Hence, in this study, TDN/Histatin 5 (His-5) was synthesized and the transport efficiency and anti-fungal effect were measured to evaluate the promotion of His-5 modified by TDNs. MATERIALS AND METHODS: Tetrahedral DNA nanostructures/His-5 complex was prepared via electrostatic attraction and characterized by transmission electron microscopy (TEM), polyacrylamide gel electrophoresis (PAGE), dynamic light scattering (DLS) and electrophoretic light scattering (ELS). The anti-fungal effect of the TDN/His-5 complex was evaluated by determining the growth curve and colony-forming units of C. albicans. The morphological transformation of C. albicans was observed by light microscope and scanning electron microscope (SEM). Immunofluorescence was performed, and potassium efflux was detected to mechanistically demonstrate the efficacy of TDN/His-5. RESULTS: The results showed that Histatin 5 modified by TDNs had preferable stability in serum and was effectively transported into C. albicans, leading to the increased formation of intracellular reactive oxygen species, higher potassium efflux and enhanced anti-fungal effect against C. albicans. CONCLUSIONS: Our study showed that TDN/His-5 was synthesized successfully. And by the modification of TDNs, His-5 showed increased transport efficiency and improved anti-fungal effect.