Platelet Membrane-Coated Curcumin-PLGA Nanoparticles Promote Astrocyte-Neuron Transdifferentiation for Intracerebral Hemorrhage Treatment.

Intracerebral hemorrhage (ICH) is a hemorrhagic disease with high mortality and disability rates. Curcumin is a promising drug for ICH treatment due to its multiple biological activities, but its application is limited by its poor watersolubility and instability. Herein, platelet membrane-coated curcumin polylactic-co-glycolic acid (PLGA) nanoparticles (PCNPs) are prepared to achieve significantly improved solubility, stability, and sustained release of curcumin. Fourier transform infrared spectra and X-ray diffraction assays indicate good encapsulation of curcumin within nanoparticles. Moreover, it is revealed for the first time that curcumin-loaded nanoparticles can not only suppress hemin-induced astrocyte proliferation but also induce astrocytes into neuron-like cells in vitro. PCNPs are used to treat rat ICH by tail vein injection, using in situ administration as control. The results show that PCNPs are more effective than curcumin-PLGA nanoparticles in concentrating on hemorrhagic lesions, inhibiting inflammation, suppressing astrogliosis, promoting neurogenesis, and improving motor functions. The treatment efficacy of intravenously administered PCNPs is comparable to that of in situ administration, indicating a good targeting effect of PCNPs on the hemorrhage site. This study provides a potent treatment for hemorrhagic injuries and a promising solution for efficient delivery of water-insoluble drugs using composite materials of macromolecules and cell membranes.

Nasal mucosa-derived mesenchymal stem cells prolonged the survival of septic rats by protecting macrophages from pyroptosis.

Sepsis is characterized by an exacerbated inflammatory response, driven by the overproduction of cytokines, a phenomenon known as a cytokine storm. This condition is further compounded by the extensive infiltration of M1 macrophages and the pyroptosis of these cells, leading to immune paralysis. To counteract this, we sought to transition M1 macrophages into the M2 phenotype and safeguard them from pyroptosis. For this purpose, we employed ectodermal mesenchymal stem cells (EMSCs) sourced from the nasal mucosa to examine their impact on both macrophages and septic animal models. The co-culture protocol involving LPS-stimulated rat bone marrow macrophages and EMSCs was employed to examine the paracrine influence of EMSCs on macrophages. The intravenous administration of EMSCs was utilized to observe the enhancement in the survival rate of septic rat models and the protection of associated organs. The findings indicated that EMSCs facilitated M2 polarization of macrophages, which were stimulated by LPS, and significantly diminished levels of pro-inflammatory cytokines and NLRP3. Furthermore, EMSCs notably restored the mitochondrial membrane potential (MMP) of macrophages through paracrine action, eliminated excess reactive oxygen species (ROS), and inhibited macrophage pyroptosis. Additionally, the systemic integration of EMSCs substantially reduced injuries to multiple organs and preserved the fundamental functions of the heart, liver, and kidney in CLP rats, thereby extending their survival.

Microfluidic Generation of Near-Infrared Photothermal Vitexin/ICG Liposome with Amplified Photodynamic Therapy.

Glioma, in which a malignant tumor cell occurs in neural mesenchymal cells, has a rapid progression and poor prognosis, which is still far from desirable in clinical treatments. We developed a lab-on-a-chip (LOC) device for the rapid and efficient preparation of vitexin/indocyanine green (ICG) liposomes. Vitexin could be released from liposome to kill cancer cell, which can potentially improve the glioma therapeutic effect and reduce the treatment time through synergistic photodynamic/photothermal therapies (PDT/PTT). The vitexin/ICG liposome was fabricated via LOC and its physicochemical property and release in vitro were evaluated. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and live/dead staining were used to examine the enhanced antitumor effect of vitexin/ICG liposome in cooperation with PDT/PTT, while the related mechanism was explored by flow cytometry and western blot. The results were as follows: (1) The prepared vitexin/ICG liposome was smaller in size, homogenous in particle size distribution with significant low polydispersity index (PDI), and enhanced cumulative release in vitro. (2) We found that the formulated liposome presented strong cancer cell inhibition and suppression of its migration in a dose-dependent manner. (3) Further mechanistic studies showed that liposome combined with near-infrared irradiation could significantly upregulate levels of B cell lymphoma 2-associated X (Bax) protein and decrease B cell lymphoma 2 (Bcl-2) at protein levels. The vitexin/ICG liposomes prepared based on a simple LOC platform can effectively enhance the solubility of insoluble drugs, and the combined effect of PTT/PDT can effectively increase their antitumor effect, which provides a simple and valid method for the clinical translation of liposomes.

Preparation, optimization, and pharmacokinetic study of nanoliposomes loaded with triacylglycerol-bound punicic acid for increased antihepatotoxic activity.

Punicic acid of pomegranate oil (PAP) has gained heightened interest due to several health benefits, such as anticarcinogenic, antidiabetic, and antiatherosclerotic properties. However, these bioactivities have been hampered by chemical instability, poor water solubility, rapid metabolism, and low bioavailability of PAP. Therefore, this study was aimed at optimizing the liposomal formulation of Triacylglycerol-bound punicic acid with its regioisomers (TPAR) for improved oral bioavailability and increased hepatoprotection through antioxidation and anti-inflammation. Herein, the optimized TPAR nanoliposome (TPAR-NL) was developed using thin-film dispersion method and subsequently characterized with appropriate indices. The optimized TPAR-NL produced fairly stable spherical nanoparticles (˂ 200 nm) with encapsulation efficiency (%EE) of 85.77%, as well as enhanced in vitro release and improved oral bioavailability. The TPAR-NL exhibited profound antihepatotoxic effect in mice pretreated with carbon tetrachloride (CCl4 ) via reduction of serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels compared with free TPAR. The TPAR-loaded liposome also significantly reduced oxidative stress by increasing superoxide dismutase and glutathione levels while lowering malonaldehyde concentration compared with the free TPAR. The TPAR-LNF further exhibited remarkable anti-inflammatory activity compared with the free drug via inhibition of interleukin-6 and tumor necrosis factor-alpha generation. Thus, the developed nanoliposomes potentiated the antihepatotoxic activity of TPAR via antioxidation and anti-inflammation.

Direct reprogramming of mouse fibroblasts into neural cells via Porphyra yezoensis polysaccharide based high efficient gene co-delivery.

BACKGROUND: The cell source for transplantation therapy is always a prerequisite question to be solved in clinical applications. Neural cells are considered non-regenerable, which highly restrict their application in the treatment for nerve injury. Therefore, neural trans-differentiation based on gene transfection provides a new solution to this issue. Compared to viral strategy, non-viral gene delivery systems are considered as a more promising way to achieve this aim. This study centers on a novel application of Porphyra yezoensis polysaccharide as a non-viral gene carrier for the neural trans-differentiation of mouse fibroblasts. RESULTS: Ethanediamine modified P. yezoensis polysaccharide (Ed-PYP) served as a gene carrier and a group of plasmids that encode Ascl1, Brn4, and Tcf3 (pABT) self-assembled into nanoparticles. Results demonstrated that Ed-PYP-pABT nanoparticles at Ed-PYP: pABT weight ratio of 40:1 was the optimal candidate for gene delivery. ELISA assay revealed the highest expression levels of NGF, BDNF and SHH at 14 days after last transfection. Immunofluorescence and western blot assays also showed robust expression of neural markers including Nestin, GFAP, ß-3tubulin, NF200, GAP43 and MAP2, in induced 3T6 cells at this time point. CONCLUSION: Overall, these findings indicated that the P. yezoensis polysaccharide-based non-viral gene co-delivery system is a promising strategy for the generation of neural cells, which might facilitate the developments in the recovery of neural injuries.

Fructus lycii oligosaccharide alleviates acute liver injury via PI3K/Akt/mTOR pathway.

Regulating the immune-environment is essential for treating acute liver injury (ALI). However, the deficiency of an effective immune balancer restricted progress. Herein, we reported an oligosaccharide from Fructus lycii oligosaccharide (FLO). To investigate the effects of FLO, we adopted primary macrophages and LO2 for experiments in vitro. In vivo, we assessed the influence of FLO in ALI with histochemical staining and enzyme indicators detection. Following that, we clarified the underlying mechanisms using western blotting and immunofluorescence. Our results indicated that FLO (100 µg/mL) showed apparent inflammatory reversal effects by shifting the phenotype of macrophages from M1 to M2 without causing any cytotoxicity. Furthermore, CCl4-induced mice were significantly improved by FLO intragastric administration. Meanwhile, PI3K/AKT/mTOR pathway was confirmed for the up-regulation of IL-10 via M2 polarization of macrophages. Collectively, our findings highlight the beneficial effects of FLO on ALI therapy via M1 to M2 macrophage conversion.

Preparation, characterization, pharmacokinetics and ulcerative colitis treatment of hyperoside-loaded mixed micelles.

At present, ulcerative colitis (UC) has become a global disease due to its high incidence. Hyperoside (HYP) is a naturally occurring flavonoid compound with many pharmacological effects. This study aimed to develop HYP-loaded mixed micelles (HYP-M) to improve oral bioavailability of HYP and to evaluate its therapeutic effect on UC. The prepared HYP-M exhibited stable physical and chemical properties, smaller particle size (PS) (21.48 ± 1.37 nm), good polydispersity index (PDI = 0.178 ± 0.013), negative Zeta potential (ZP) (- 20.00 ± 0.48 mV) and high entrapment rate (EE) (89.59 ± 2.03%). In vitro release and in vivo pharmacokinetic results showed that HYP-M significantly increased the releasing rate of HYP, wherein its oral bioavailability was 4.15 times higher than that of free HYP. In addition, HYP-M was more effective in the treatment of UC than free HYP. In conclusion, HYP-M could serve as a novel approach to improve bioavailability and increase anti-UC activity of HYP.

The applications of 3D printing in wound healing: The external delivery of stem cells and antibiosis.

As the global number of chronic wound patients rises, the financial burden and social pressure on patients increase daily. Stem cells have emerged as promising tissue engineering seed cells due to their enriched sources, multidirectional differentiation ability, and high proliferation rate. However, delivering them in vitro for the treatment of skin injury is still challenging. In addition, bacteria from the wound site and the environment can significantly impact wound healing. In the last decade, 3D bioprinting has dramatically enriched cell delivery systems. The produced scaffolds by this technique can be precisely localized within cells and perform antibacterial actions. In this review, we summarized the 3D bioprinting-based external delivery of stem cells and their antibiosis to improve wound healing.

Microfluidic fabricated bisdemethoxycurcumin thermosensitive liposome with enhanced antitumor effect.

Bisdemethoxycurcumin (BDMC) is the main active ingredient that is isolated from Zingiberaceae plants, wherein it has excellent anti-tumor effects. However, insolubility in water limits its clinical application. Herein, we reported a microfluidic chip device that can load BDMC into the lipid bilayer to form BDMC thermosensitive liposome (BDMC TSL). The natural active ingredient glycyrrhizin was selected as the surfactant to improve solubility of BDMC. Particles of BDMC TSL had small size, homogenous size distribution, and enhanced cultimulative release in vitro. The anti-tumor effect of BDMC TSL on human hepatocellular carcinomas was investigated via 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, live/dead staining, and flowcytometry. These results showed that the formulated liposome had a strong cancer cell inhibitory, and presented a dose-dependent inhibitory effect on migration. Further mechanistic studies showed that BDMC TSL combined with mild local hyperthermia could significantly upregulate B cell lymphoma 2 associated X protein levels and decrease B cell lymphoma 2 protein levels, thereby inducing cell apoptosis. The BDMC TSL that was fabricated via microfluidic device were decomposed under mild local hyperthermia, which could beneficially enhance the anti-tumor effect of raw insoluble materials and promote translation of liposome.

Hybrid Membrane-Derived Nanoparticles for Isoliquiritin Enhanced Glioma Therapy.

Due to the obstruction and heterogeneity of the blood-brain barrier, the clinical treatment of glioma has been extremely difficult. Isoliquiritigenin (ISL) exhibits antitumor effects, but its low solubility and bioavailability limit its application potential. Herein, we established a nanoscale hybrid membrane-derived system composed of erythrocytes and tumor cells. By encapsulating ISL in hybrid membrane nanoparticles, ISL is expected to be enhanced for the targeting and long-circulation in gliomas therapy. We fused erythrocytes with human glioma cells U251 and extracted the fusion membrane via hypotension, termed as hybrid membrane (HM). HM-camouflaged ISL nanoparticles (ISL@HM NPs) were prepared and featured with FT-IR, SEM, TEM, and DLS particle analysis. As the results concluded, the ISL active pharmaceutical ingredients (APIs) were successfully encapsulated with HM membranes, and the NPs loading efficiency was 38.9 ± 2.99% under maximum entrapment efficiency. By comparing the IC50 of free ISL and NPs, we verified that the solubility and antitumor effect of NPs was markedly enhanced. We also investigated the mechanism of the antitumor effect of ISL@HM NPs, which revealed a marked inhibition of tumor cell proliferation and promotion of senescence and apoptosis of tumor cells of the formulation. In addition, the FSC and WB results examined the effects of different concentrations of ISL@HM NPs on tumor cell disruption and apoptotic protein expression. Finally, it can be concluded that hybridized membrane-derived nanoparticles could prominently increase the solubility of insoluble materials (as ISL), and also enhance its targeting and antitumor effect.

Liquiritin-Hydroxypropyl-Beta-Cyclodextrin Inclusion Complex: Preparation, Characterization, Bioavailability and Antitumor Activity Evaluation.

The pharmacological activities of liquiritin (LT) are greatly limited by its insolubility and low oral absorption. The purpose of this study was to prepare LT-hydroxypropyl-beta-cyclodextrin inclusion complex (LT-HP-ß-CD) to increase water solubility, oral bioavailability and antitumor effect of LT. Herein, saturated aqueous solution method was applied to prepare the LT-HP-ß-CD prior to characterization via scanning electron microscope (SEM), infrared radiation (IR) spectroscopy, X-ray diffraction analysis (XRD), and differential scanning calorimetry (DSC). Also, in vitro release and in vivo pharmacokinetics were evaluated. Moreover, the anti-tumor activity of the formulation was investigated in the A549 lung cancer cells. The results of SEM, IR, XRD and DSC showed that LT-HP-ß-CD was successfully formulated. In vitro release and oral bioavailability of LT-HP-ß-CD compared with the free LT was significantly higher. Successfully, antitumor effect of LT was remarkably enhanced by the preparation of LT-HP-ß-CD. Altogether, the LT-HP-ß-CD represents a potential carrier for enhancing the water solubility and oral bioavailability of LT coupled with antitumor activity enhancement.

LBO-EMSC Hydrogel Serves a Dual Function in Spinal Cord Injury Restoration via the PI3K-Akt-mTOR Pathway.

It is critical to obtain an anti-inflammatory microenvironment when curing spinal cord injury (SCI). On the basis of this, we prepared Lycium barbarum oligosaccharide (LBO)-nasal mucosa-derived mesenchymal stem cells (EMSCs) fibronectin hydrogel for SCI restoration via inflammatory license effect and M2 polarization of microglias. LBO exhibited remarkable M2 polarization potential for microglia. However, EMSCs primed by LBO generated enhanced paracrine effects through the inflammatory license-like process. The observed dual function is likely based on the TNFR2 pathway. In addition, LBO-EMSC hydrogel possesses a synergistic effect on M2 polarization of microglia through the PI3K-Akt-mTOR signaling pathway. The obtained findings provide a simple approach for MSC-based therapies for SCI and shed more light on the role of TNFR2 on bidirectional regulation in tissue regeneration.

3D printable Sodium alginate-Matrigel (SA-MA) hydrogel facilitated ectomesenchymal stem cells (EMSCs) neuron differentiation.

Ectomesenchymal stem cells (EMSCs) are typical adult stem cells obtained from the cranial neural crest. They have the potential to differentiate into various cell types, such as osseous cells, neurons and glial cells. Three-dimensional (3 D) printing is a novel method to construct biological structures by rapid prototyping. Previously, our group reported on the stemness and multi-lineage differentiation potential of EMSCs on gels. However, the exploration of EMSCs in 3 D printing and then evaluation of the growth and neuronal differentiation of EMSCs on extruded 3 D printable hybrid hydrogels has not been reported. Therefore, the current study explored the novel hybrid Sodium alginate-Matrigel (SA-MA) hydrogel extruded 3 D printing to design an in vitro scaffold to promote the differentiation and growth of EMSCs. In addition, the physical properties of the hydrogel were characterized and its drug-releasing property determined. Notably, the results showed that the construct exhibited a sustain-released effect of growth factor BDNF in accordance with the Higuchi equation. Moreover, the cell survival rate on the 3 D printed scaffold was 88.22 ± 1.13% with higher neuronal differentiation efficiency compared with 2 D culture. Thus, SA-MA's ability to enhanced EMSCs neuronal differentiation offers a new biomaterial for neurons regeneration in the treatment of spinal cord injury.

EMSCs Build an All-in-One Niche via Cell-Cell Lipid Raft Assembly for Promoted Neuronal but Suppressed Astroglial Differentiation of Neural Stem Cells.

The therapeutic efficiency of allogenic/intrinsic neural stem cells (NSCs) after spinal cord injury is severely compromised because the hostile niche at the lesion site incurs massive astroglial but not neuronal differentiation of NSCs. Although many attempts are made to reconstruct a permissive niche for nerve regeneration, solely using a living cell material to build an all-in-one, multifunctional, permissive niche for promoting neuronal while inhibiting astroglial differentiation of NSCs is not reported. Here, ectomesenchymal stem cells (EMSCs) are reported to serve as a living, smart material that creates a permissive, all-in-one niche which provides neurotrophic factors, extracellular matrix molecules, cell-cell contact, and favorable substrate stiffness for directing NSC differentiation. Interestingly, in this all-in-one niche, a corresponding all-in-one signal-sensing platform is assembled through recruiting various niche signaling molecules into lipid rafts for promoting neuronal differentiation of NSCs, and meanwhile, inhibiting astrocyte overproliferation through the connexin43/YAP/14-3-3θ pathway. In vivo studies confirm that EMSCs can promote intrinsic NSC neuronal differentiation and domesticating astrocyte behaviors for nerve regeneration. Collectively, this study represents an all-in-one niche created by a single-cell material-EMSCs for directing NSC differentiation.

Human chorionic plate-derived mesenchymal stem cells transplantation restores ovarian function in a chemotherapy-induced mouse model of premature ovarian failure.

BACKGROUND: Previous studies have reported that transplantation of mesenchymal stem cells (MSCs) from many human tissues could ameliorate ovarian dysfunction. However, no study has revealed the therapeutic efficiency of MSCs derived from the chorionic plate (CP-MSCs) for premature ovarian failure (POF). METHODS: We investigated the restorative effects of CP-MSCs on cyclophosphamide (CTX)-induced POF. The POF mouse models were established via intraperitoneal injection of 50 mg/kg CTX into female mice for 15 consecutive days. After that, CP-MSCs were intravenously transplanted into the mice once a week for 4 weeks. The serum estradiol (E2) and follicle-stimulating hormone (FSH) levels in the mouse models were detected using enzyme-linked immunosorbent assay (ELISA) before and after treatment. Ovarian function was evaluated through counting the follicles, estrous cycles, and oocytes. RESULTS: CP-MSC transplantation restored the serum hormone level and ovarian function of the mice in the mouse model of POF induced by CTX. The levels of serum E2 and FSH in the POF model group was 232.33 ± 17.16 pg/mL and 4.48 ± 0.29 mIU/mL, respectively, after 6 weeks of treatment, which were similar to the values in the wild-type (WT) group. The superovulation demonstrated that ovarian function was significantly improved compared with nontreated POF model mice. The CP-MSC transplantation could restore CTX-induced ovarian dysfunction. CONCLUSIONS: Our results offer a potential application for human CP-MSCs in POF treatment.

A novel formulation of [6]-gingerol: Proliposomes with enhanced oral bioavailability and antitumor effect.

[6]-Gingerol, one of the components of the rhizome of Ginger, has a variety of biological activities such as anticoagulant, antioxidative, antitumor, anti-inflammatory, antihypertensive, and so forth. However, as one of the homologous phenolic ketones, [6]-gingerol is insoluble in water which limits its applications. Herein, we prepared [6]-gingerol proliposomes through modified thin-film dispersion method, which was spherical or oval, and physicochemically stable with narrow size distribution. Surprisingly, in vitro release of [6]-gingerol loaded proliposome compared with the free [6]-gingerol was significantly higher and its oral bioavailability increased 5-fold in vivo. Intriguingly, its antitumor effect was enhanced in the liposome formulation. Thus, our prepared [6]-gingerol proliposome proved to be a novel formulation for [6]-gingerol, which significantly improved its antitumor effect.

Photoluminescent Cationic Carbon Dots as efficient Non-Viral Delivery of Plasmid SOX9 and Chondrogenesis of Fibroblasts.

With the increasing demand for higher gene carrier performance, a multifunctional vector could immensely simplify gene delivery for disease treatment; nevertheless, the current non- viral vectors lack self-tracking ability. Here, a type of novel, dual-functional cationic carbon dots (CDs), produced through one-step, microwave-assisted pyrolysis of arginine and glucose, have been utilized as both a self-imaging agent and a non-viral gene vector for chondrogenesis from fibroblasts. The cationic CDs could condense the model gene plasmid SOX9 (pSOX9) to form ultra-small (10-30 nm) nanoparticles which possessed several favorable properties, including high solubility, tunable fluorescence, high yield, low cytotoxicity and outstanding biocompatibility. The MTT assay indicated that CDs/pSOX9 nanoparticles had little cytotoxicity against mouse embryonic fibroblasts (MEFs) compared to Lipofectamine2000 and PEI (25 kDa). Importantly, the CDs/pSOX9 nanoparticles with tunable fluorescence not only enabled the intracellular tracking of the nanoparticles, but also could successfully deliver the pSOX9 into MEFs with significantly high efficiency. Furthermore, the CDs/pSOX9 nanoparticles-mediated transfection of MEFs showed obvious chondrogenic differentiation. Altogether, these findings demonstrated that the CDs prepared in this study could serve as a paradigmatic example of the dual-functional reagent for both self-imaging and effective non-viral gene delivery.

Neural differentiation of fibroblasts induced by intracellular co-delivery of Ascl1, Brn2 and FoxA1 via a non-viral vector of cationic polysaccharide.

Direct reprogramming of other somatic cells into neurons is an alternative strategy for the recovery of an injured nervous system. In this work, we developed a new non-viral gene carrier based on Porphyra yezoensis polysaccharide (PYP). After modification with ethylenediamine, the cationized PYP (Ed-PYP) was combined with plasmids encoding Ascl1, Brn2 and FoxA1 to form spherical nanoscale particles (Ed-PYP-pABF nanoparticles). Cytotoxicity assays proved that Ed-PYP-pABF nanoparticles had a better safety profile than Lipofectamine 2000 and polyetherimide. Characterization tests illustrated that the Ed-PYP-pABF nanoparticles at an Ed-PYP:pABF weight ratio of 40:1 is a potential candidate for gene delivery, which was further supported by Western blot and plasmid encoding enhanced green fluorescence protein transfection. Based on this transfection strategy, we co-delivered pABF to 3T6 cells using Ed-PYP. ELISA indicated that the levels of brain-derived neurotrophic factor, nerve growth factors and sonic hedgehog reached a maximum at 14 days after the last transfection. Immunofluorescence and Western blot further exhibited positive expression of neurofilament 200, Nestin, glial fibrillary acidic protein, growth associated protein-43, ß-3tubulin, and microtubule associated protein 2, proving the successful conversion of 3T6 cells into neurons. Taken together, these results illustrated that a natural polysaccharide-based gene co-delivery system is a promising strategy for neural reprogramming.

Porphyra polysaccharide-derived carbon dots for non-viral co-delivery of different gene combinations and neuronal differentiation of ectodermal mesenchymal stem cells.

In this study, multifunctional fluorescent carbon dots (CDs) were synthesized using a one-pot hydrothermal carbonization reaction, with the naturally-occurring porphyra polysaccharide (PPS) serving as a single carbon source for the first time and ethylenediamine (Ed) acting as the surface passivation agent. The resulting CDs enjoyed a high quantum yield (56.3%), excitation-dependent fluorescence, small size (<10 nm), spherical shape, uniform distribution, positive surface charge, low cytotoxicity and excellent ability to condense macromolecular plasmid DNA. The synthesized CDs were employed for neuronal induction from ectodermal mesenchymal stem cells for the first time via highly efficient non-viral gene delivery. The optimal combination of factors (Ascl1 and Brn2) was selected from seven different combinations out of Ascl1, Brn2 and Sox2 according to the expression of neuronal markers (Tuj1, Map2 and Tau). The results of qRT-PCR demonstrated that the CDs possessed a significantly higher transfection efficiency than the commercially available transfection reagents PEI (25 kDa) and Lipofectamine2000. Moreover, the CDs/pDNA nanoparticles exhibited more efficient neuronal differentiation of the EMSCs than the AT-RA-containing induction medium. Furthermore, the CDs/pDNA nanoparticles could enter cells via both caveolae- and clathrin-mediated endocytosis. Taken together, the natural polysaccharide PPS-derived CDs enriched the current application of CDs by employing the CDs as a novel non-viral gene carrier for neuronal differentiation of adult stem cells, which held great promise in tissue engineering and bioimaging.

Cationic carbon quantum dots derived from alginate for gene delivery: One-step synthesis and cellular uptake.

UNLABELLED: Carbon quantum dots (CQDs), unlike semiconductor quantum dots, possess fine biocompatibility, excellent upconversion properties, high photostability and low toxicity. Here, we report multifunctional CQDs which were developed using alginate, 3% hydrogen peroxide and double distilled water through a facile, eco-friendly and inexpensive one-step hydrothermal carbonization route. In this reaction, the alginate served as both the carbon source and the cationization agent. The resulting CQDs exhibited strong and stable fluorescence with water-dispersible and positively-charged properties which could serve as an excellent DNA condensation. As non-viral gene vector being used for the first time, the CQDs showed considerably high transfection efficiency (comparable to Lipofectamine2000 and significantly higher than PEI, p<0.05) and negligible toxicity. The photoluminescence properties of CQDs also permitted easy tracking of the cellular-uptake. The findings showed that both caveolae- and clathrin-mediated endocytosis pathways were involved in the internalization process of CQDs/pDNA complexes. Taken together, the alginate-derived photoluminescent CQDs hold great potential in biomedical applications due to their dual role as efficient non-viral gene vectors and bioimaging probes. STATEMENT OF SIGNIFICANCE: This manuscript describes a facile and simple one-step hydrothermal carbonization route for preparing optically tunable photoluminescent carbon quantum dots (CQDs) from a novel raw material, alginate. These CQDs enjoy low cytotoxicity, positive zeta potential, excellent ability to condense macromolecular DNA, and most importantly, notably high transfection efficiency. The interesting finding is that the negatively-charged alginate can convert into positively charged CQDs without adding any cationic reagents. The significance of this study is that the cationic carbon quantum dots play dual roles as both non-viral gene vectors and bioimaging probes at the same time, which are most desirable in many fields of applications such as gene therapy, drug delivery, and bioimaging.