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1.
PLoS One ; 19(5): e0302216, 2024.
Article in English | MEDLINE | ID: mdl-38781198

ABSTRACT

The real-time monitoring on the risk status of the vehicle and its driver can provide the assistance for the early detection and blocking control of single-vehicle accidents. However, complex risk coupling relationship is one of the main features of single-vehicle accidents with high mortality rate. On the basis of investigating the coupling effect among multi-risk factors and establishing a safety management database throughout the life cycle of vehicles, single-vehicle driving risk network (SVDRN) with a three-level threshold was developed, and its topology features were analyzed to assessment the importance of nodes. To avoid the one-sidedness of single indicator, the multi-attribute comprehensive evaluation model was applied to measure the comprehensive effect of characteristic indicators for nodes importance. A algorithm for real-time monitoring of vehicle driving risk status was proposed to identify key risk chains. The result revealed that improper operation, speeding, loss of vehicle control and inefficient driver management were the sequence of top four risk factors in the comprehensive evaluation result of nodes importance (mean value = 0.185, SD = 0.119). There were minor differences of 0.017 in the node importance among environmental factors, among which non-standard road alignment had the larger value. The improper operation and non-standard road alignment were the highest combination correlation of factors affecting road safety, with the support of 51.81% and the confidence of 69.35%. This identification algorithm of key risk chains that combines node importance and its risk state threshold can effectively determine the high-frequency risk transmission paths and risk factors through multi-vehicle test, providing a basis for centralization management of transport enterprises.


Subject(s)
Accidents, Traffic , Algorithms , Accidents, Traffic/prevention & control , Accidents, Traffic/statistics & numerical data , Risk Factors , Humans , Automobile Driving , Risk Assessment/methods
2.
Small ; : e2308335, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38420895

ABSTRACT

Tumor-derived exosomes (TDEs) induced extracellular microenvironment has recently been validated to be critical for tumor progression and metastasis, however, remodeling it for oncotherapy still remains a major challenge due to difficulty in regulation of TDEs secretion. Herein, the supramolecular chiral nanofibers, composed of L/D -phenylalanine derivates (L/D-Phe) and linear hyaluronic acid (HA), are successfully employed to construct TDEs induced anti-tumor extracellular microenvironment. The left-handed L-Phe @HA nanofibers significantly inhibit TDEs secretion into extracellular microenvironment, which results in suppression of tumor proliferation and metastasis in vitro and vivo. Biological assays and theoretical modeling reveal that these results are mainly attributed to strong adsorption of the key exosomes transporters (Ras-related protein Rab-27A and synaptosome-associated protein 23) on left-handed L-Phe @HA nanofibers via enhanced stereoselective interaction, leading to degradation and phosphorylated dropping of exosomes transporters. Subsequently, transfer function of exosomes transporters is limited, which causes remarkable inhibition of TDEs secretion. These findings provide a promising novel insight of chiral functional materials to establish an anti-tumor extracellular microenvironment via regulation of TDEs secretion.

3.
Adv Sci (Weinh) ; 11(5): e2303495, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38037850

ABSTRACT

Sodium aescinate (SA) shows great potential for treating lymphedema since it can regulate the expression of cytokines in M1 macrophages, however, it is commonly administered intravenously in clinical practice and often accompanied by severe toxic side effects and short metabolic cycles. Herein, SA-loaded chiral supramolecular hydrogels are prepared to prove the curative effects of SA on lymphedema and enhance its safety and transdermal transmission efficiency. In vitro studies demonstrate that SA- loaded chiral supramolecular hydrogels can modulate local immune responses by inhibiting M1 macrophage polarization. Typically, these chiral hydrogels can significantly increase the permeability of SA with good biocompatibility due to the high enantioselectivity between chiral gelators and stratum corneum and L-type hydrogels are found to have preferable drug penetration over D-type hydrogels. In vivo studies show that topical delivery of SA via chiral hydrogels results in dramatic therapeutic effects on lymphedema. Specifically, it can downregulate the level of inflammatory cytokines, reduce the development of fibrosis, and promote the regeneration of lymphatic vessels. This study initiates the use of SA for lymphedema treatment and for the creation of an effective chiral biological platform for improved topical administration.


Subject(s)
Hydrogels , Macrophages , Saponins , Triterpenes , Administration, Cutaneous , Cytokines
4.
Angew Chem Int Ed Engl ; 62(24): e202303812, 2023 Jun 12.
Article in English | MEDLINE | ID: mdl-37069482

ABSTRACT

The induction of diverse chirality regulation in nature by multiple binding sites of biomolecules is ubiquitous and plays an essential role in determining the biofunction of biosystems. However, mimicking this biological phenomenon and understanding at a molecular level its mechanism with the multiple binding sites by establishing an artificial system still remains a challenge. Herein, abundant chirality inversion is achieved by precisely and multiply manipulating the co-assembled binding sites of phenylalanine derivatives (D/LPPF) with different naphthalene derivatives (NA, NC, NP, NF). The amide and hydroxy group of naphthalene derivatives prefer to bind with the carboxy group of LPPF, while carboxylic groups and fluoride atoms tend to bind with the amide moiety of LPPF. All these diverse interaction modes can precisely trigger helicity inversion of LPPF nanofibers. In addition, synergistically manipulating the carboxy and amide binding sites from a single LPPF molecule to simultaneously interact with different naphthalene derivatives leads to chirality regulation. Typically, varying the solvent may switch the interaction modes and the switched new interaction modes can be employed to further regulate the chirality of the LPPF nanofibers. This study may provide a novel approach to explore chirality diversity in artificial systems by regulating the intermolecular binding sites.

5.
ACS Nano ; 17(7): 6275-6291, 2023 04 11.
Article in English | MEDLINE | ID: mdl-36946387

ABSTRACT

Revascularization plays a critical role in the healing of diabetic wounds. Accumulation of advanced glycation end products (AGEs) and refractory multidrug resistant bacterial infection are the two major barriers to revascularization, directly leading to impaired healing of diabetic wounds. Here, an artfully designed chiral gel dressing is fabricated (named as HA-LM2-RMR), which consists of l-phenylalanine and cationic hexapeptide coassembled helical nanofibers cross-linked with hyaluronic acid via hydrogen bonding. This chiral gel possesses abundant chiral and cationic sites, not only effectively reducing AGEs via stereoselective interaction but also specifically killing multidrug resistant bacteria rather than host cells since cationic hexapeptides selectively interact with negatively charged microbial membrane. Surprisingly, the HA-LM2-RMR fibers present an attractive ability to activate sprouted angiogenesis of Human Umbilical Vein Endothelial Cells by upregulating VEGF and OPA1 expression. In comparison with clinical Prontosan Wound Gel, the HA-LM2-RMR gel presents superior healing efficiency in the infected diabetic wound with respect to angiogenesis and re-epithelialization, shortening the healing period from 21 days to 14 days. These findings for chiral wound dressing provide insights for the design and construction of diabetic wound dressings that target revascularization, which holds great potential to be utilized in tissue regenerative medicine.


Subject(s)
Diabetes Mellitus , Endothelial Cells , Humans , Wound Healing , Bandages , Peptides/pharmacology , Glycation End Products, Advanced/pharmacology
6.
Chemistry ; 29(9): e202202735, 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36404280

ABSTRACT

Being able to precisely manipulate both the morphology and chiroptical signals of supramolecular assemblies will help to better understand the natural biological self-assembly mechanism. Two simple l/d-phenylalanine-based derivatives (L/DPFM) have been designed, and their solvent-dependent morphology evolutions are illustrated. It was found that, as the content of H2 O in aqueous ethanol solutions was increased, LPFM self-assembles first into right-handed nanofibers, then flat fibrous structures, and finally inversed left-handed nanofibers. Assemblies in ethanol and H2 O exhibit opposite conformations and circular dichroism (CD) signals even though they are constructed from the same molecules. Thus, the morphology-dependent cell adhesion and proliferation behaviors are further characterized. Left-handed nanofibers are found to be more favorable for cell adhesion than right-handed nanostructures. Quantitative AFM analysis showed that the L929 cell adhesion force on left-handed LPFM fibers is much higher than that on structures with inversed handedness. Moreover, the value of cell Young's modulus is lower for left-handed nanofibrous films, which indicates better flexibility. The difference in cell-substrate interactions might lead to different effects on cell behavior.


Subject(s)
Nanofibers , Nanostructures , Solvents , Cell Adhesion , Nanostructures/chemistry , Nanofibers/chemistry , Ethanol
7.
Acta Biomater ; 153: 204-215, 2022 11.
Article in English | MEDLINE | ID: mdl-36108967

ABSTRACT

Cancer recurrence remains a major challenge after primary tumor excision, and the inflammation of tumor-caused wounds can hinder wound healing and potentially promote tumor growth. Herein, a chiral L-phenylalanine-based (LPFEG) supramolecular hydrogel system encapsulated with polydopamine nanoparticles (PDA-NPs) has been developed in order to prevent tumor relapse after surgery and promote wound repair. PDA-NPs allow for near-infrared (NIR) light-triggered photothermal therapy, especially, it can scavenge free radicals in the surgical wound. LPFEG can mimic native extracellular matrix (ECM) structure to create a chiral microenvironment that enhances fibroblast adhesion, proliferation, and new tissue regeneration. With anticancer drug doxorubicin (DOX) loaded into the composite hydrogel, the antitumor effect is significantly enhanced by the integration of chemo-photothermal therapy both in vitro and in vivo. The PDA-based chiral supramolecular composite hydrogel as an effective postoperative adjuvant possesses promising applicable prospects in inhibiting tumor recurrence and accelerating wound healing after operation. STATEMENT OF SIGNIFICANCE: After primary tumor excision, cancer recurrence remains a severe concern, and the inflammation induced by tumor-related wounds can delay wound healing. Herein, we designed a chiral L-phenylalanine-based (LPFEG) supramolecular hydrogel platform that was co-assembled with polydopamine nanoparticles (PDA-NPs). Among them, PDA-NPs can offer photothermal therapy and scavenge free radicals in surgical wounds. LPFEG can create a chiral microenvironment that promotes fibroblast adhesion, proliferation, and new tissue regeneration. Furthermore, with anticancer drug doxorubicin (DOX) loaded into the composite hydrogel, the antitumor effect is considerably boosted. Therefore, the PDA-based chiral supramolecular hydrogel shows high application potential as a postoperative adjuvant in preventing tumor relapse as well as accelerating wound healing after surgery.


Subject(s)
Antineoplastic Agents , Hyperthermia, Induced , Humans , Hydrogels/pharmacology , Hydrogels/chemistry , Neoplasm Recurrence, Local/drug therapy , Doxorubicin/chemistry , Wound Healing , Antineoplastic Agents/pharmacology , Phenylalanine , Inflammation/drug therapy , Tumor Microenvironment
8.
Angew Chem Int Ed Engl ; 61(46): e202211812, 2022 11 14.
Article in English | MEDLINE | ID: mdl-36173979

ABSTRACT

Kinetic co-assembly pathway induced chirality inversion along with morphology transition is of importance to understand biological processes, but still remains a challenge to realize in artificial systems. Herein, helical nanofibers consisting of phenylalanine-based enantiomers (L/DPF) successfully transform into kinetically trapped architectures with opposite helicity through a kinetic co-assembly pathway. By contrast, the co-assemblies obtained by a thermodynamic pathway exhibit non-helical structures. The formation sequence of non-covalent interactions plays a crucial role in structural chirality of co-assemblies. For the kinetic pathway, the hydrogen bonding between D/LPF and naphthylamide derivatives forms before π-π stacking to facilitate the formation of helical structures with inverse handedness. This study may provide an approach to explore chirality inversion accompanied by morphology transition by manipulating the kinetic co-assembly pathway.


Subject(s)
Phenylalanine , Hydrogen Bonding , Stereoisomerism , Kinetics , Thermodynamics
9.
Gels ; 8(7)2022 Jul 13.
Article in English | MEDLINE | ID: mdl-35877522

ABSTRACT

Chronic refractory wounds are one of the most serious complications of diabetes, and the effects of common treatments are limited. Chiral hydrogel combined with dimethyloxalyglycine (DMOG) as a dressing is a promising strategy for the treatment of chronic wounds. In this research, we have developed a DMOG-loaded supramolecular chiral amino-acid-derivative hydrogel for wound dressings for full-thickness skin regeneration of chronic wounds. The properties of the materials, the ability of sustained release drugs, and the ability to promote angiogenesis were tested in vitro, and the regeneration rate and repair ability of full-thickness skin were tested in vivo. The chiral hydrogel had the ability to release drugs slowly. It can effectively promote cell migration and angiogenesis in vitro, and promote full-thickness skin regeneration and angiogenesis in vivo. This work offers a new approach for repairing chronic wounds completely through a supramolecular chiral hydrogel loaded with DMOG.

11.
ACS Nano ; 15(9): 14972-14984, 2021 09 28.
Article in English | MEDLINE | ID: mdl-34491712

ABSTRACT

How the three-dimensional (3D) chiral environment affects the biocatalysis remains an important issue, thereby inspiring the development of a microenvironment that highly mimics the natural features of enzyme to guarantee enhanced biocatalysis. In this study, two gelators bearing d/l-phenylalanine as chiral centers are designed to construct the 3D chiral catalytic microenvironment for enhancing the biocatalysis of lipase. Such a microenvironment is programmed through chiral transmission of chirality from molecular chirality to achiral polymers. It shows that the chirality of the microenvironment evidently influences the catalytic efficiency of immobilized lipase inside the system, and the 3D microenvironment constructed by right-handed helical nanostructures can enhance the catalytic activity of lipase inside as high as 10-fold for catalyzing 4-nitrophenyl palmitate (NPP) to 4-nitrophenol (NP) and 1.4-fold for catalyzing lipids to triglycerides (TGs) in 3T3-L1 cells than that of the achiral microenvironment. Moreover, the 3D chiral microenvironment has the merits of good catalytic efficiency, high storage stability, and efficient recyclability. This strategy of designing a 3D chiral microenvironment suitable for biocatalysis will overcome the present limitations of enzymatic immobilization in traditional materials and enhance the understanding of biocatalysis.


Subject(s)
Biocatalysis
12.
Chemistry ; 27(60): 14911-14920, 2021 Oct 25.
Article in English | MEDLINE | ID: mdl-34347917

ABSTRACT

Fabricating structural complex assemblies from simple amino acid-based derivatives is attracting great research interests due to their easy accessibility and preparation. However, the morphological regulation of racemates (an equimolar mixture of enantiomers) were largely overlooked. In this work, through rational modulation of kinetic and thermodynamic parameters, we achieved multiple dimensional architectures employing tryptophan-based racemate (RPWM). Upon assembling, 1D bundled nanofibers, 2D lamellar nanostructure and 3D urchin-like microflowers could be obtained depending on the solvents used. The corresponding morphology evolutions were successfully illustrated by changing the enantiomeric excess (ee) value. Moreover, for RPWM, uniform 0D nanospheres were formed in H2 O under 4 °C, which could spontaneously convert into lamella under ambient temperature. Taking advantages of its temperature-responsive phase change behavior, RPWM assemblies exhibited excellent removal efficiency for organic dye RhB, and could be reused for several consecutive cycles without significant changes in its removal performance. Taken together, it's rational to envision that the engineering of racemates assembly pathways can greatly increase the robustness in a wide variety of supramolecular materials and further lead to their blooming versatile applications.


Subject(s)
Nanospheres , Tryptophan , Amino Acids , Stereoisomerism , Thermodynamics
13.
Bioact Mater ; 6(4): 990-997, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33102941

ABSTRACT

Retinal degeneration is a main class of ocular diseases. So far, retinal progenitor cell (RPC) transplantation has been the most potential therapy for it, in which promoting RPCs neuronal differentiation remains an unmet challenge. To address this issue, innovatively designed L/ d - phenylalanine based chiral nanofibers (LPG and DPG) are employed and it finds that chirality of fibers can efficiently regulate RPCs differentiation. qPCR, western blot, and immunofluorescence analysis show that right-handed helical DPG nanofibers significantly promote RPCs neuronal differentiation, whereas left-handed LPG nanofibers decrease this effect. These effects are mainly ascribed to the stereoselective interaction between chiral helical nanofibers and retinol-binding protein 4 (RBP4, a key protein in the retinoic acid (RA) metabolic pathway). The findings of chirality-dependent neuronal differentiation provide new strategies for treatment of neurodegenerative diseases via optimizing differentiation of transplanted stem cells on chiral nanofibers.

14.
Bioact Mater ; 6(6): 1563-1574, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33294734

ABSTRACT

Magnesium alloys are promising biomaterials for orthopedic implants because of their degradability, osteogenic effects, and biocompatibility. Magnesium has been proven to promote distraction osteogenesis. However, its mechanism of promoting distraction osteogenesis is not thoroughly studied. In this work, a high-purity magnesium pin developed and applied in rat femur distraction osteogenesis. Mechanical test, radiological and histological analysis suggested that high-purity magnesium pin can promote distraction osteogenesis and shorten the consolidation time. Further RNA sequencing investigation found that alternative Wnt signaling was activated. In further bioinformatics analysis, it was found that the Hedgehog pathway is the upstream signaling pathway of the alternative Wnt pathway. We found that Ptch protein is a potential target of magnesium and verified by molecular dynamics that magnesium ions can bind to Ptch protein. In conclusion, HP Mg implants have the potential to enhance bone consolidation in the DO application, and this process might be via regulating Ptch protein activating Hedgehog-alternative Wnt signaling.

15.
Chemistry ; 27(9): 3119-3129, 2021 Feb 10.
Article in English | MEDLINE | ID: mdl-33225542

ABSTRACT

Although chiral nanostructures have been fabricated at various structural levels, the transfer and amplification of chirality from molecules to supramolecular self-assemblies are still puzzling, especially for heterochiral molecules. Herein, four series of C2 -symmetrical dipeptide-based derivatives bearing various amino acid sequences and different chiralities are designed and synthesized. The transcription and amplification of molecular chirality to supramolecular assemblies are achieved. The results show that supramolecular chirality is only determined by the amino acid adjacent to the benzene core, irrespective of the absolute configuration of the C-terminal amino acid. In addition, molecular chirality also has a significant influence on the gelation behavior. For the diphenylalanine-based gelators, the homochiral gelators can be gelled through a conventional heating-cooling process, whereas heterochiral gelators form translucent stable gels under sonication. The racemic gels possess higher mechanical properties than those of the pure enantiomers. All of these results contribute to an increasing knowledge over control of the generation of specific chiral supramolecular structures and the development of new optimized strategies to achieve functional supramolecular organogels through heterochiral and racemic systems.

16.
Small ; 16(47): e2004756, 2020 11.
Article in English | MEDLINE | ID: mdl-33136317

ABSTRACT

Supramolecular assemblies with diverse morphologies are crucial in determining their biochemical or physical properties. However, the topological evolution and self-assembly intermediates as well as the mechanism remain elusive. Herein, a dynamic morphological evolution from solid nanospheres to superhelical nanofibers is revealed via self-assembly of a minimal l-tryptophan-based derivative (LPWM) with various mixed solvent combinations, including the formation of solid nanospheres, the fusion of nanospheres into pearling necklace, the disintegration of necklace into short nanofibers, the distortion of nanofibers into nanotwists, and the entanglement of nanotwists into superhelices. It is found that the breakage of intramolecular H-bonds and reconstruction of intermolecular H-bonds, as well as the variation of aromatic interactions and hydrophobic effects, are the key driving forces for topological transformation, especially the dimensional evolution. The nanospheres and nanofibers demonstrate discrepant behaviors towards mouse neural stem cell (NSC) differentiation that compared with negligible impact of nanospheres scaffold, the nanofibers scaffold is favorable for NSC differentiation into neurons. The remarkable dynamic regulation of assembly process, together with the NSC differentiation on twisted nanofibers are making this system an ideal model to interpret complex proteins fibrillation processes and investigate the structure-function relationship.

17.
ACS Nano ; 14(12): 17151-17162, 2020 Dec 22.
Article in English | MEDLINE | ID: mdl-33202135

ABSTRACT

Controlling the handedness of dynamic helical nanostructures of supramolecular assemblies by external stimuli is of great fundamental significance with appealing morphology-dependent applications. Significantly, access to in situ chirality transformation of dynamic multistimuli-responsive systems can provide channels for real-time monitoring of the transfer processes in biological systems. However, efforts to achieve helix inversion in an all-gel-state and to comprehend the phenomena at a molecular scale are scarce. Herein, we introduce an example of supramolecular hydrogel in which graphene oxide (GO) incorporation leads to opposite helicity of the l-phenylalanine derivative (LPFEG) upon UV irradiation. The gelator modulates different degrees of packing that are responsible for the initial construction of right-handed nanofibers in GO surfaces and for the change in helix to preferred left-handedness in RGO surfaces caused by GO reduction. Specifically, LPFEG shows a mixture of right- and left-handed nanofibers with an appropriate exposure to UV light. A thermal-reversible transformation of chirality is also discovered in the supramolecular assemblies, allowing a dynamic and invertible flip of helicity upon heating and cooling. The morphology transformation makes the hybrid an ideal candidate for application in a precisely controlled drug delivery process. It can unexpectedly serve as a photosensitizer and a carrier for enantioselective absorption of specific chiral drugs enantiomer (l-dopa and S-naproxen sodium) and also exhibit on-demand drug release due to the helix reversal induced by light irradiation. Our results illustrate how the surface reactivity can direct the helical organization of adsorbed fibers, which in turn provide control over enantioselective absorption of chiral drug enantiomers, further giving rise to on-demand drug release due to handedness inversion upon UV irradiation.

18.
J Biomater Appl ; 35(2): 224-236, 2020 08.
Article in English | MEDLINE | ID: mdl-32460592

ABSTRACT

Distraction osteogenesis has widespread clinical use in the treatment of large bone defects. Nonetheless, the prolonged consolidation period carries the risk of complications. Magnesium-based materials have been shown to promote bone regeneration in fracture healing both in vitro and in vivo. Here, we investigated whether high-purity magnesium could enhance bone formation in distraction osteogenesis. High-purity magnesium pins were placed into the medullary cavity in the rat distraction osteogenesis model. Results showed that the bone volume/total tissue volume, bone mineral density, and mechanical properties of new callus were significantly higher in the high-purity magnesium group compared to stainless steel and control group (p < 0.01). Histological analyses confirmed improved bone consolidation and vascularization in high-purity magnesium group. Further, polymerase chain reaction-array investigation, Western blot, and immunohistochemical results found that vascular endothelial growth factor and hypoxia inducible factor-1α were highly expressed in the high-purity magnesium group, while Von Hippel-Lindau protein was the opposite (p < 0.01). In conclusion, high-purity magnesium implants have the potential to enhance angiogenesis and bone consolidation in the distraction osteogenesis application, and this process might be via the regulation of Von Hippel-Lindau/hypoxia inducible factor-1α/vascular endothelial growth factor signaling.


Subject(s)
Biocompatible Materials/pharmacology , Bone Nails , Magnesium/pharmacology , Osteogenesis, Distraction , Osteogenesis/drug effects , Angiogenesis Inducing Agents/chemistry , Angiogenesis Inducing Agents/pharmacology , Animals , Biocompatible Materials/chemistry , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Magnesium/chemistry , Male , Osteogenesis, Distraction/methods , Rats, Sprague-Dawley , Signal Transduction/drug effects , Vascular Endothelial Growth Factor A/metabolism , Von Hippel-Lindau Tumor Suppressor Protein/metabolism
19.
Acc Chem Res ; 53(4): 852-862, 2020 04 21.
Article in English | MEDLINE | ID: mdl-32216333

ABSTRACT

Chirality exits from molecular-level, supramolecular, and nanoscaled helical structures to the macroscopic level in biological life. Among these various levels, as the central structural motifs in living systems (e.g., double helix in DNA, α-helix, ß-sheet in proteins), supramolecular helical systems arising from the asymmetrical spatial stacking of molecular units play a crucial role in a wide diversity of biochemical reactions (e.g., gene replication, molecular recognition, ion transport, enzyme catalysis, and so on). However, the importance of supramolecular chirality and its potential biofunctions has not yet been fully explored. Thus, generating chiral assembly to transfer nature's chiral code to artificial biomaterials is expected to be utilized for developing novel functional biomaterials. As one of the most commonly used biomaterials, supramolecular hydrogels have attracted considerable research interest due to their resemblance to the structure and function of the native extracellular matrix (ECM). Therefore, the performance and manipulation of chiral assembled nanoarchitectures in supramolecular hydrogels may provide useful insights into understanding the role of supramolecular chirality in biology.In this Account, recent progress on chiral supramolecular hydrogels is presented, including how to construct and regulate assembled chiral nanostructures in hydrogels with controllable handedness and then use them to develop chiral hydrogels that could be applied in biology, biochemistry, and medicine. First, a brief introduction is provided to present the basic concept related to supramolecular chirality and the importance of supramolecular chirality in living systems. The chiral assemblies in supramolecular hydrogels are strongly driven by noncovalent interactions between molecular building blocks (such as hydrogen bonding, π-π stacking, hydrophobic, and van der Waals interactions). Consequently, the handedness of these chiral assemblies can be regulated by many extra stimuli including solvents, temperature, pH, metal ions, enzymes, and photoirradiation, which is presented in the second section. This manipulation of the chirality of nanoarchitectures in supramolecular hydrogels can result in the development of potential biofunctions. For example, specific supramolecular chirality-induced biological phenomena (such as controlled cell adhesion, proliferation, differentiation, apoptosis, protein adsorption, drug delivery, and antibacterial adhesion) are presented in detail in the third section. Finally, the outlook of open challenges and future developments of this rapidly evolving field is provided. This account that highlights the diverse chirality-dependent biological phenomena not only helps us to understand the importance of chirality in life but also provides new ideas for designing and preparing chiral materials for more bioapplications.


Subject(s)
Biocompatible Materials/chemistry , Hydrogels/chemistry , Animals , Humans , Stereoisomerism
20.
Langmuir ; 36(10): 2524-2533, 2020 03 17.
Article in English | MEDLINE | ID: mdl-32090561

ABSTRACT

The development of enantioselective recognition is of great significance in medical science and pharmaceutical industry, which associates with the molecular recognition phenomenon widely observed in biological systems. In particular, the facile and straight achievement of visual enantioselective recognition has been drawing increasing consideration, but it is still a challenge. Herein, a heterochiral diphenylalanine-based gelator (LFDF) is synthesized, presenting left-handed nanofibers during self-assembly in ethanol, which accomplishes the phenylalaninol enantiomer recognition on multiple platforms. When adding l- or d-phenylalaninol into LFDF supramolecular solution followed by ultrasonic treatment, precipitate and gel are formed, respectively. Meanwhile, LFDF supramolecular gel completely collapses in a minute after dropping l-phenylalaninol, while the gel almost remains when d-type is employed. Moreover, a fluorescent supramolecular xerogel (ThT-LFDF) is fabricated by combining the LFDF gelator with thioflavine T (ThT), which could detect l-phenylalaninol accompanying with fluorescence quenching while d-type with barely decreasing. And the ThT-LFDF xerogel system shows a good sensitivity (reaches to ppm) for the detection of l-phenylalaninol. It is found that the chirality of the assembled nanofibers, as well as amino and carboxyl of phenylalaninol, plays a critical role on the discrimination process. The multiple and visible enantioselective recognition of phenylalaninol through chiral supramolecular self-assemblies shows potential applications in the fields of medical science and pharmaceutical industry.

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