Genipin, a natural blue colorant precursor: Source, extraction, properties, and applications

Genipin-enriched chitosan-Zein nanoparticles for improved curcumin encapsulation

Polysaccharide-protein nanocomplexes are considered one of the desired systems to encapsulate bioactive compounds. The study prepared chitosan (CS)/genipin (GP)/zein nanoparticles with chemical cross-linkage for encapsulating and releasing curcumin. Fourier transform infrared spectra demonstrated that cross-linkage between molecules was attributed to electrostatic interactions and the formation of amido bonds and hydrogen bonding. Transmission electron microscopy showed that all prepared nanoparticles showed a spherical morphology. Particularly, cinnamaldehyde screening -NH2 groups in CS significantly reduced the encapsulation efficiency of nanoparticles, demonstrating the significant role of the -NH2 group in CS-coated zein nanoparticles. Additionally, the encapsulation efficiency was largely increased to 82.3 % at the ratio of CS/GP/zein (w/w, 20:1:100), compared with 38.4 % using zein as a single encapsulation for curcumin. In vitro digestion, the addition of GP and CS decreased the release of curcumin from 84.8 % to 57.1 % after the initial digestion of 2 h. The GP/CS/zein particles retained 12 % of curcumin after 6- h of digestion, indicating the improvements in encapsulation efficiency and release properties.

Genipin-crosslinked hydrogels for food and biomedical applications: A scientometric review

Genipin, a precursor of dietary blue pigment, is a promising alternative for industrial applications in food and health. Due to its ability to simultaneously satisfy biosafety requirements and provide crosslinking effects, genipin has attracted considerable attention for food and biomedical applications. In this review, we attempt to shed light on the progress in genipin research using scientometrics. Based on this scientometric discovery, we reviewed the use of genipin-crosslinked films for fruit packaging in food science. Genipin-crosslinked hydrogels used for drug delivery include natural, chemical, and protein delivery systems. Genipin-crosslinked hydrogels for tissue engineering primarily include materials used for tissue regeneration and repair. Genipin-crosslinked hydrogels are used in wound dressings and wound closure. This review provides a scientometric perspective to facilitate future research and development of genipin for food science, drug delivery, tissue engineering, and wound healing.

Repurposed genipin targeting UCP2 exhibits antitumor activity through inducing ferroptosis in glioblastoma

Uncoupling protein-2 (UCP2) controls the antioxidant response and redox homeostasis in cancer and is considered a potent molecular target for cancer treatment. However, the specific mechanism of UCP2 inhibition and its role in glioblastoma (GBM) have not yet been elucidated. Here, we attempt to identify a UCP2 inhibitor and study the underlying molecular mechanism in GBM. Bioinformatics analysis and immunohistochemistry are used to validate the high expression of UCP2 in GBM and its prognostic significance. Drug intervention and tumor xenograft experiments are conducted to determine the inhibitory effect of genipin, a UCP2 inhibitor, on UCP2. The mitochondrial membrane potential and key ferroptosis genes are examined to determine the occurrence of ferroptosis. High expression of UCP2 in GBM is associated with poor prognosis, and inhibiting UCP2 can alleviate the malignant behavior of GBM tumors. Genipin can downregulate the expression of GPX4 and upregulate the expression of ACSL4 by inhibiting UCP2, leading to ferroptosis and alleviating the malignant behavior of tumors. In summary, UCP2 is a potential therapeutic target for GBM. Genipin, which targets UCP2, effectively inhibits GBM development by inducing ferroptosis in vivo and in vitro. These findings indicate that genipin treatment based on UCP2 targeting has potential therapeutic applications with a clinical perspective for the treatment of GBM patients.

Implantation of biomimetic polydopamine nanocomposite scaffold promotes optic nerve regeneration through modulating inhibitory microenvironment

Optic nerve regeneration remains challenging worldwide due to the limited intrinsic regenerative capacity of retinal ganglion cells (RGCs) and the inhibitory microenvironment. Oxidative stress, induced by excessive reactive oxygen species (ROS) following optic nerve injury, is associated with prolonged neuroinflammation, resulting in a secondary injury of RGCs and the impairment of axon regeneration. Herein, we developed a bionic nanocomposite scaffold (GA@PDA) with immunoregulatory ability for enhanced optic nerve regeneration. The ice-templating method was employed to fabricate biopolymer-based scaffolds with a directional porous structure, mimicking the optic nerve, which effectively guided the oriented growth of neuronal cells. The incorporation of bioinspired polydopamine nanoparticles (PDA NPs) further confers excellent ROS scavenging ability, thereby modulating the phenotype transformation of microglia/macrophages from pro-inflammatory M1 to anti-inflammatory M2. In a rat optic nerve crush model, the implantation of GA@PDA scaffold enhanced survival of RGCs and promoted axonal regeneration. Our study offers novel insights and holds promising potential for the advancement of engineered biomaterials in facilitating optic nerve regeneration.

A five-in-one novel MOF-modified injectable hydrogel with thermo-sensitive and adhesive properties for promoting alveolar bone repair in periodontitis: Antibacterial, hemostasis, immune reprogramming, pro-osteo-/angiogenesis and recruitment

Periodontitis is a chronic inflammatory disease caused by plaque that destroys the alveolar bone tissues, resulting in tooth loss. Poor eradication of pathogenic microorganisms, persistent malignant inflammation and impaired osteo-/angiogenesis are currently the primary challenges to control disease progression and rebuild damaged alveolar bone. However, existing treatments for periodontitis fail to comprehensively address these issues. Herein, an injectable composite hydrogel (SFD/CS/ZIF-8@QCT) encapsulating quercetin-modified zeolitic imidazolate framework-8 (ZIF-8@QCT) is developed. This hydrogel possesses thermo-sensitive and adhesive properties, which can provide excellent flowability and post-injection stability, resist oral fluid washout as well as achieve effective tissue adhesion. Inspirationally, it is observed that SFD/CS/ZIF-8@QCT exhibits a rapid localized hemostatic effect following implantation, and then by virtue of the sustained release of zinc ions and quercetin exerts excellent collective functions including antibacterial, immunomodulation, pro-osteo-/angiogenesis and pro-recruitment, ultimately facilitating excellent alveolar bone regeneration. Notably, our study also demonstrates that the inhibition of osteo-/angiogenesis of PDLSCs under the periodontitis is due to the strong inhibition of energy metabolism as well as the powerful activation of oxidative stress and autophagy, whereas the synergistic effects of quercetin and zinc ions released by SFD/CS/ZIF-8@QCT are effective in reversing these biological processes. Overall, our study presents innovative insights into the advancement of biomaterials to regenerate alveolar bone in periodontitis.

Genipa americana L.: A Review on Traditional Uses, Phytochemistry and Biological Activities

Genipa americana L. (Rubiaceae), genip tree, has therapeutic and nutritional potential. This revision aimed to gather information on botanical characteristics, popular uses, phytochemical, and pharmacological aspects of the tree. The methodology adopted integrated literature published between 2000 and 2024, as well as consultations with the World International Intellectual Property Organization (WIPO); resulting in 39 articles and 11 patents to promote this research. The species, which is native and not endemic to Brazil, is most prevalent in the Amazon biome as it is suitable for reconstructing degraded areas, as well as having various traditional applications. Iridoids are the main secondary metabolites present in the species, especially ginipin, geniposide acid, and geniposide, which are the most prevalent in the fruit. The patents registered with the WIPO indicate its use as a colorant, insecticide, anti-inflammatory, and antioxidant potential, in evidence of its antimicrobial and antioxidant activities. Further studies are needed on the mechanisms of the chemical components' action and on ethnopharmacology.

Advances in the mechanisms of Gardenia jasminoides Ellis in improving diabetes and its complications

Gardenia jasminoides Ellis (Zhi-zi), which belongs to the Rubiaceae family, has been used mainly with its fry fruit for thousands of years, and it is an herb with the homology of medicine and food. In traditional Chinese medicine (TCM) theory, Zhi-zi can be used for "Quench Xiaoke", meaning for therapying diabetes in modern medicine. Based on numerous pharmacological studies, Gardenia jasminoides Ellis (Zhi-zi), and its ingredients, mainly including iridoid glycosides and carotenoids (crocins), possess potent antioxidant and anti-inflammatory properties, and can promote insulin secretion and sensitization, stimulate GLP-1 pathway activity, and protect islet β cells and the macro- and microvascular systems. These properties are the primary reasons why Zhi-zi and its ingredients are effective in reducing glucose levels, treating diabetes, and preventing its complications. This review aims to summarize the current situation and the advances of the studies on the mechanisms of Zhi-zi in improving diabetes and its complications, and it is expected to provide useful and systematic references for future research and clinical application of Zhi-zi and its active ingredients in the therapy of diabetes and complications.

Rheological Characterization of Genipin-Based Crosslinking Pigment and O-Carboxymethyl Chitosan-Oxidized Hyaluronic Acid In Situ Formulable Hydrogels

The aim of this study was to develop a material capable of rapidly absorbing bodily fluids and forming a resilient, adhesive, viscoelastic hydrogel in situ to prevent post-surgical adhesions. This material was formulated using O-carboxymethyl chitosan (O-CMCS), oxidized hyaluronic acid (OHA), and a crosslinking pigment derived from genipin and glutamic acid (G/GluP). Both crosslinked (O-CMCS/OHA-G/GluP) and non-crosslinked hydrogels (O-CMCS/OHA) were evaluated using a HAAKE™ MARS™ rheometer for their potential as post-surgical barriers. A rheological analysis, including dynamic oscillatory measurements, revealed that the crosslinked hydrogels exhibited significantly higher elastic moduli (G'), indicating superior gel formation and mechanical stability compared to non-crosslinked hydrogels. The G/GluP crosslinker enhanced gel stability by increasing the separation between G' and G″ and achieving a lower loss tangent (tan δ < 1.0), indicating robustness under dynamic physiological conditions. The rapid hydration and gelation properties of the hydrogels underscore their effectiveness as physical barriers. Furthermore, the O-CMCS/OHA-G/GluP hydrogel demonstrated rapid self-healing and efficient application via spraying or spreading, with tissue adherence and viscoelasticity to facilitate movement between tissues and organs, effectively preventing adhesions. Additionally, the hydrogel proved to be both cost effective and scalable, highlighting its potential for clinical applications aimed at preventing post-surgical adhesions.

Teicoplanin-Decorated Reduced Graphene Oxide Incorporated Silk Protein Hybrid Hydrogel for Accelerating Infectious Diabetic Wound Healing and Preventing Diabetic Foot Osteomyelitis

Developing hybrid hydrogel dressings with anti-inflammatory, antioxidant, angiogenetic, and antibiofilm activities with higher bone tissue penetrability to accelerate diabetic wound healing and prevent diabetic foot osteomyelitis (DFO) is highly desirable in managing diabetic wounds. Herein, the glycopeptide teicoplanin is used for the first time as a green reductant to chemically reduce graphene oxide (GO). The resulting teicoplanin-decorated reduced graphene oxide (rGO) is incorporated into a mixture of silk proteins (SP) and crosslinked with genipin to yield a physicochemically crosslinked rGO-SP hybrid hydrogel. This hybrid hydrogel exhibits high porosity, self-healing, shear-induced thinning, increased cell proliferation and migration, and mechanical properties suitable for tissue engineering. Moreover, the hybrid hydrogel eradicates bacterial biofilms with a high penetrability index in agar and hydroxyapatite disks covered with biofilms, mimicking bone tissue. In vivo, the hybrid hydrogel accelerates the healing of noninfected wounds in a diabetic rat and infected wounds in a diabetic mouse by upregulating anti-inflammatory cytokines and downregulating matrix metalloproteinase-9, promoting M2 macrophage polarization and angiogenesis. The implantation of hybrid hydrogel into the infected site of mouse tibia improves bone regeneration. Hence, the rGO-SP hybrid hydrogel can be a promising wound dressing for treating infectious diabetic wounds, providing a further advantage in preventing DFO.

New Findings Regarding the Effects of Selected Blue Food Colorants (Genipin, Patent Blue V, and Brilliant Blue FCF) on the Hemostatic Properties of Blood Components In Vitro

Natural and synthetic colorants present in food can modulate hemostasis, which includes the coagulation process and blood platelet activation. Some colorants have cardioprotective activity as well. However, the effect of genipin (a natural blue colorant) and synthetic blue colorants (including patent blue V and brilliant blue FCF) on hemostasis is not clear. In this study, we aimed to investigate the effects of three blue colorants-genipin, patent blue V, and brilliant blue FCF-on selected parameters of hemostasis in vitro. The anti- or pro-coagulant potential was assessed in human plasma by measuring the following coagulation times: thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (APTT). Moreover, we used the Total Thrombus formation Analysis System (T-TAS, PL-chip) to evaluate the anti-platelet potential of the colorants in whole blood. We also measured their effect on the adhesion of washed blood platelets to fibrinogen and collagen. Lastly, the cytotoxicity of the colorants against blood platelets was assessed based on the activity of extracellular lactate dehydrogenase (LDH). We observed that genipin (at all concentrations (1-200 µM)) did not have a significant effect on the coagulation times (PT, APTT, and TT). However, genipin at the highest concentration (200 µM) and patent blue V at the concentrations of 1 and 10 µM significantly prolonged the time of occlusion measured using the T-TAS, which demonstrated their anti-platelet activity. We also observed that genipin decreased the adhesion of platelets to fibrinogen and collagen. Only patent blue V and brilliant blue FCF significantly shortened the APTT (at the concentration of 10 µM) and TT (at concentrations of 1 and 10 µM), demonstrating pro-coagulant activity. These synthetic blue colorants also modulated the process of human blood platelet adhesion, stimulating the adhesion to fibrinogen and inhibiting the adhesion to collagen. The results demonstrate that genipin is not toxic. In addition, because of its ability to reduce blood platelet activation, genipin holds promise as a novel and valuable agent that improves the health of the cardiovascular system and reduces the risk of cardiovascular diseases. However, the mechanism of its anti-platelet activity remains unclear and requires further studies. Its in vivo activity and interaction with various anti-coagulant and anti-thrombotic drugs, including aspirin and its derivatives, should be examined as well.

Near-infrared-II responsive ovalbumin functionalized gold-genipin nanosystem cascading photo-immunotherapy of cancer

Synergistic cancer therapies have attracted wide attention owing to their multi-mode tumor inhibition properties. Especially, photo-responsive photoimmunotherapy demonstrates an emerging cancer treatment paradigm that significantly improved treatment efficiency. Herein, near-infrared-II responsive ovalbumin functionalized Gold-Genipin nanosystem (Au-G-OVA NRs) was designed for immunotherapy and deep photothermal therapy of breast cancer. A facile synthesis method was employed to prepare the homogeneous Au nanorods (Au NRs) with good dispersion. The nanovaccine was developed further by the chemical cross-linking of Au-NRs, genipin and ovalbumin. The Au-G-OVA NRs outstanding aqueous solubility, and biocompatibility against normal and cancer cells. The designed NRs possessed enhanced localized surface plasmon resonance (LSPR) effect, which extended the NIR absorption in the second window, enabling promising photothermal properties. Moreover, genipin coating provided complimentary red fluorescent and prepared Au-G-OVA NRs showed significant intracellular encapsulation for efficient photoimmunotherapy outcomes. The designed nanosystem possessed deep photothermal therapy of breast cancer and 90% 4T1 cells were ablated by Au-G-OVA NRs (80μg ml-1concentration) after 1064 nm laser irradiation. In addition, Au-G-OVA NRs demonstrated outstanding vaccination phenomena by facilitating OVA delivery, antigen uptake, maturation of bone marrow dendritic cells, and cytokine IFN-γsecretion for tumor immunosurveillance. The aforementioned advantages permit the utilization of fluorescence imaging-guided photo-immunotherapy for cancers, demonstrating a straightforward approach for developing nanovaccines tailored to precise tumor treatment.

Quaternized chitosan/oxidized bacterial cellulose cryogels with shape recovery for noncompressible hemorrhage and wound healing

Management of noncompressible torso hemorrhage is an urgent clinical requirement, desiring biomaterials with rapid hemostasis, anti-infection and excellent resilient properties. In this research, we have prepared a highly resilient cryogel with both hemostatic and antibacterial effects by chemical crosslinking and electrostatic interaction. The network structure crosslinked by quaternized chitosan and genipin was interspersed with oxidized bacterial cellulose after lyophilization. The as-prepared cryogel can quickly return to the original volume when soaking in water or blood. The appropriately sized pores in the cryogel help to absorb blood cells and further activate coagulation, while the quaternary ammonium salt groups on quaternized chitosan inhibit bacterial infections. Both cell and animal experiments showed that the cryogel was hypotoxic and could promote the regeneration of wound tissue. This research provides a new pathway for the preparation of double crosslinking cryogels and offers effective and safe biomaterials for the emergent bleeding management of incompressible wounds.