The stability of heparin-coated liposomes in plasma and their effect on its coagulation

Construction of nanoparticles from blueberry anthocyanins-lecithin/gum Arabic improves lipid droplet accumulation and gut microbiota disturbance in HFD-induced obese mice

The digestive instability of anthocyanins (ACNs) limits their application in food nutrition, especially precision nutrition. Blueberry ACNs-loaded nanoparticles (Lipo/GA-ACNs NPs) were prepared using gum arabic (GA) as the delivery carrier and liposomal vesicles (Lipo) prepared from soy lecithin as the targeting scaffold. The average particle size of the NPs was 99.4 nm, and the polydispersion index (PDI) was 0.46. The results showed that the presence of the Lipo-GA matrix enhanced the NPs' in vitro stability and antioxidant activity. In addition, the in vitro biocompatibility, uptake ability, lipid-lowering activity, and free-radical scavenging ability were improved to a certain extent. In a high-fat diet (HFD)-induced obese mouse model, oral administration of ACNs-LNP (LNP, liver-targeted nanoparticle) showed better effects on body weight, liver injury, and lipid droplet accumulation in the liver than ACNs. In addition, ACNs-LNP also played a role in regulating HFD-induced gut microbiota imbalance. These results provide a promising ACNs delivery strategy with the potential to be developed into a functional food that targets the liver to prevent fatty liver.

Biomaterials-Based Regenerative Strategies for Skin Tissue Wound Healing

Skin tissue wound healing proceeds through four major stages, including hematoma formation, inflammation, and neo-tissue formation, and culminates with tissue remodeling. These four steps significantly overlap with each other and are aided by various factors such as cells, cytokines (both anti- and pro-inflammatory), and growth factors that aid in the neo-tissue formation. In all these stages, advanced biomaterials provide several functional advantages, such as removing wound exudates, providing cover, transporting oxygen to the wound site, and preventing infection from microbes. In addition, advanced biomaterials serve as vehicles to carry proteins/drug molecules/growth factors and/or antimicrobial agents to the target wound site. In this review, we report recent advancements in biomaterials-based regenerative strategies that augment the skin tissue wound healing process. In conjunction with other medical sciences, designing nanoengineered biomaterials is gaining significant attention for providing numerous functionalities to trigger wound repair. In this regard, we highlight the advent of nanomaterial-based constructs for wound healing, especially those that are being evaluated in clinical settings. Herein, we also emphasize the competence and versatility of the three-dimensional (3D) bioprinting technique for advanced wound management. Finally, we discuss the challenges and clinical perspective of various biomaterial-based wound dressings, along with prospective future directions. With regenerative strategies that utilize a cocktail of cell sources, antimicrobial agents, drugs, and/or growth factors, it is expected that significant patient-specific strategies will be developed in the near future, resulting in complete wound healing with no scar tissue formation.

Nano-drug delivery systems in wound treatment and skin regeneration

Skin damages are defined as one of most common lesions people suffer from, some of wounds are notoriously difficult to eradicate such as chronic wounds and deep burns. Existing wound therapies have been proved to be inadequate and far from satisfactory. The cutting-edge nanotechnology offers an unprecedented opportunity to revolutionize and invent new therapies or boost the effectiveness of current medical treatments. In particular, the nano-drug delivery systems anchor bioactive molecules to applied area, sustain the drug release and explicitly enhance the therapeutic efficacies of drugs, thus making a fine figure in field relevant to skin regeneration. This review summarized and discussed the current nano-drug delivery systems holding pivotal potential for wound healing and skin regeneration, with a special emphasis on liposomes, polymeric nanoparticles, inorganic nanoparticles, lipid nanoparticles, nanofibrous structures and nanohydrogel.

Coadministration of Oligomeric Hyaluronic Acid-Modified Liposomes with Tumor-Penetrating Peptide-iRGD Enhances the Antitumor Efficacy of Doxorubicin against Melanoma

A safe and efficient tumor-targeting strategy based on oligomeric hyaluronic acid (HA) modification and coadministration of tumor-penetrating peptide-iRGD was successfully developed. In this study, common liposomes (cLip) were modified by oligomeric HA to obtain HA-Lip. After injection into rats, HA-Lip showed good stealth in the bloodstream and lower liver distribution compared with cLip. Moreover, our HA-Lip could be internalized into B16F10 cells (CD44-overexpressing tumor cells) through HA-CD44 interaction. After systemic administration to B16F10 melanoma-bearing mice, HA-Lip showed an increased distribution in tumor due to the prolonged blood circulation time and the enhanced penetration and retention effect. When coadministered with iRGD, the tumor penetration of HA-Lip was significantly enhanced, which could promote HA-Lip internalization by tumors cells located in deep tumor regions through receptor-mediated endocytosis. Furthermore, doxorubicin (DOX)-loaded HA-Lip coadministering with iRGD showed much better antitumor effect compared to DOX-loaded cLip and DOX-loaded cLip in combination with iRGD. In systemic toxicity test, DOX-loaded HA-Lip could significantly decrease the cardiotoxicity and myelosuppression of DOX. Taken together, our results demonstrated that coadministration of oligomeric HA-modified liposomes with iRGD could be a promising treatment strategy for targeted therapy of melanoma.

Controlled release of heparin-binding growth factors using heparin-containing particulate systems for tissue regeneration

The strategy of growth factor delivery to specific sites for therapeutic applications has been considered an essential process in biomedical fields despite some obstacles, such as a non-controlled release with initial burst. This article focuses on particulate systems using heparin for the controlled delivery of heparin-binding growth factors (HBGFs), an emerging area in the tissue engineering field. Since heparin has been widely utilized for growth factor delivery due to its electrostatic nature and specific affinity with HBGFs, heparin-containing polymeric particulates can be utilized as functional carriers to deliver growth factors in a controlled manner. In particular, examples of the HBGF delivery systems containing heparin, perspectives and potential applications are described and discussed.

Research on thymopentin loaded oralN-trimethyl chitosan nanoparticles

Peptides, although high efficacy and specificity in their physiological function, usually have low therapeutical activities due to their poor bioavailability when administrated orally. Nanoparticles have been regarded as a useful vector for targeted drug delivery system because they can protect drug from being degraded quickly and pass the gastrointestinal barriers. Here we described a novel oral N-trimethyl chitosan nanoparticles formulation containing thymopentin (Tp5-TMC-NP). N-trimethyl chitosan (TMC) was synthesized and then used to prepare Tp5-TMC-NP by ionotropic gelation. A three-factor, five-level CCD (Central Composite Design) design was used in the optimization procedure, with HPLC as the analyzing method. The resulting Tp5-TMC-NP had a regular spherical surface and a narrow particle size range with a mean diameter of 110.6 nm. The average entrapment efficiency was 78.8%. The lyophilized Tp5-TMC-NP formulation was stable in 4 degrees C or -20 degrees C after storage of 3 months without obvious changes in morphology, particle size, pH and entrapment ratio. The results of the flow cytometer determination showed that the ratio of CD4+/CD8+ of Wistar female rat givenTp5-TMC-NP (ig) was 2.59 time that of the group given Tp5 (ig).

Interactions of functionalized dextran-coated liposomes with vascular smooth muscle cells

Synthetic polymers are commonly used in the medical field as implants, polymeric drugs, or drug delivery systems. Among them, bioactive sulfated polysaccharides such as chemically modified dextrans are described to exhibit various properties including the inhibition of smooth muscle cell (SMC) growth. SMCs are key cellular components involved in the physiopathology of the vascular walls especially in atherosclerosis or after vascular surgeries. Interestingly, binding sites on vascular SMCs were already observed for an antiproliferative functionalized dextran (FDx). In this context, we hypothesized that this bioactive polymer could be used as a targeting moiety on the surface of drug delivery systems. In this work, liposomes constituted of phosphatidylcholine, phosphatidylethanolamine and cholesterol (70/10/20 mol.%) were prepared and coated with FDx hydrophobized by a cholesterol anchor (CholFDx) which penetrates the lipid bilayer during the liposome formation. The liposome interactions with SMCs were then followed using radiolabeled liposomes and fluorolabeled liposomes. Results of radioactivity on SMCs indicated higher interactions with CholFDx-coated liposomes as compared to uncoated liposomes. The fluorescence of cells incubated with fluorolabeled CholFDx-coated liposomes also evidenced the liposome binding on SMC membranes. These data demonstrated that liposomes coated with FDx interacted with vascular SMCs. Consequently, the coating with such bioactive polymers appears promising for the design of new drug delivery systems for the targeting of vascular cells.

Liposomes coated with chemically modified dextran interact with human endothelial cells

Some liposomal formulations are now in clinical use. New applications in biology and medicine using targeted liposomes remain an intensive research area. In this context, liposomes constituted of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cholesterol (70/10/20 mol %) were prepared by detergent dialysis and coated with dextran (Dx) or functionalized dextran (FDx), both hydrophobized by a cholesterol anchor which penetrates the lipid bilayer during the vesicle formation. The coating of liposomes with these polysaccharides was performed because chemically modified dextran but not native Dx interacted with vascular cells. The liposome uptake by human endothelial cells was followed using uncoated and coated liposomes radiolabeled with a neutral lipid (3H-cholesterol) and a polar phospholipid (14C-PC). The results indicated for both radiolabels a preferential uptake by endothelial cells of FDx-coated liposomes compared to uncoated or Dx-coated liposomes. Addition to the culture medium of calcium up to 10 mM further enhanced the level and rate of incorporation of FDx-coated liposomes, whereas interaction of endothelial cells with uncoated liposomes or liposomes coated with Dx was poorly affected. Liposome membranes were then labeled with N-(lissamine rhodamine B sulfonyl)diacyl-PE and liposome uptake by endothelial cells was observed by fluorescence microscopy. The punctate intracellular fluorescence of cells incubated at 37 degrees C with fluorolabeled liposomes is indicative of the liposome localization within the endocytotic pathway of the cells. Altogether, these data demonstrate that coating of liposomes with FDx enable specific interactions with human endothelial cells in culture. Consequently, these liposomes coated with bioactive polymers represent an attractive approach as materials for use as drug delivery vehicles targeting vascular cells.