ABSTRACT
Regenerating periodontal defects in osteoporosis patients presents a significant clinical challenge. Unlike the relatively straightforward regeneration of homogeneous bone tissue, periodontal regeneration requires the intricate reconstruction of the cementum-periodontal ligament-alveolar bone interface. Strontium (Sr)-doped biomaterials have been extensively utilized in bone tissue engineering due to their remarkable pro-osteogenic attributes. However, their application in periodontal tissue regeneration has been scarcely explored. In this study, we synthesized an innovative injectable Sr-BGN/GNM scaffold by integrating Sr-doped bioactive glass nanospheres (Sr-BGNs) into the nanofiber architecture of gelatin nanofiber microspheres (GNMs). This design, mimicking the natural bone extracellular matrix (ECM), enhanced the scaffold's mechanical properties and effectively controlled the sustained release of Sr ions (Sr2+), thereby promoting the proliferation, osteogenic differentiation, and ECM secretion of PDLSCs and BMSCs, as well as enhancing vascularization in endothelial cells. In vivo experiments further indicated that the Sr-BGNs/GNMs significantly promoted osteogenesis and angiogenesis. Moreover, the scaffold's tunable degradation kinetics optimized the prolonged release and pro-regenerative effects of Sr2+ in vivo, matching the pace of periodontal regeneration and thereby facilitating the regeneration of functional periodontal tissues under osteoporotic conditions. Therefore, Sr-BGNs/GNMs emerge as a promising candidate for advancing periodontal regeneration strategies.
Subject(s)
Extracellular Matrix , Microspheres , Nanofibers , Osteoporosis , Strontium , Strontium/chemistry , Strontium/pharmacology , Nanofibers/chemistry , Osteoporosis/drug therapy , Humans , Extracellular Matrix/chemistry , Extracellular Matrix/drug effects , Extracellular Matrix/metabolism , Animals , Osteogenesis/drug effects , Tissue Scaffolds/chemistry , Cell Differentiation/drug effects , Tissue Engineering , Cell Proliferation/drug effects , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/cytology , Regeneration/drug effectsABSTRACT
INTRODUCTION: The mechanosensitive ion channel, Piezo1, is responsible for transducing mechanical stimuli into intracellular biochemical signals and has been identified within periodontal ligament cells (PDLCs). Nonetheless, the precise biologic function of Piezo1 in the regulation of alveolar bone remodeling by PDLCs during compressive forces remains unclear. Therefore, this study focused on elucidating the role of the Piezo1 channel in alveolar bone remodeling and uncovering its underlying mechanisms. METHODS: PDLCs were subjected to compressive force and Piezo1 inhibitors. Piezo1 and ß-catenin expressions were quantified by quantitative reverse transcription polymerase chain reaction and Western blot. The intracellular calcium concentration was measured using Fluo-8 AM staining. The osteogenic and osteoclastic activities were assessed using alkaline phosphatase staining, enzyme-linked immunosorbent assay, quantitative reverse transcription polymerase chain reaction, and Western blot. In vivo, orthodontic tooth movement was used to determine the effects of Piezo1 on alveolar bone remodeling. RESULTS: Piezo1 and activated ß-catenin expressions were upregulated under compressive force. Piezo1 inhibition reduced ß-catenin activation, osteogenic differentiation, and osteoclastic activities. ß-catenin knockdown reversed the increased osteogenic differentiation but had little impact on osteoclastic activities. In vivo, Piezo1 inhibition led to decreased tooth movement distance, accompanied by reduced ß-catenin activation and expression of osteogenic and osteoclastic markers on the compression side. CONCLUSIONS: The Piezo1 channel is a key mechanotransduction component of PDLCs that senses compressive force and activates ß-catenin to regulate alveolar bone remodeling.
Subject(s)
Osteogenesis , beta Catenin , Humans , beta Catenin/metabolism , Cells, Cultured , Mechanotransduction, Cellular , Periodontal Ligament , Bone Remodeling/physiology , Cell Differentiation/physiologyABSTRACT
The aims of the study were to degrade the anti-nutritional factors (ANFs) such as phytic acid, glycinin, and ß-conglycinin and improve the values of soybean meal (SBM). Firstly, in this study, a strain PY-4B which exhibited the best enzymatic activities of protease (403.3 ± 17.8 U/mL) and phytase (62.9 ± 2.9 U/mL) was isolated and screened among the isolates. Based on the analysis of physiological and biochemical characteristics and 16S rDNA sequence, the strain PY-4B was identified and named as Pseudomonas PY-4B. Next, Pseudomonas PY-4B was applied to fermentation of SBM. The results showed that the contents of glycinin and ß-conglycinin were decreased by 57-63%, and the phytic acid was remarkably degraded by 62.5% due to the fermentation of SBM by Pseudomonas PY-4B. The degradation of glycinin and ß-conglycinin resulted in increase of contents of water-soluble proteins and amino acids in fermented SBM. Moreover, Pseudomonas PY-4B exhibited no hemolytic activity and slight inhibitory effect on the growth of pathogen Staphylococcus aureus and the wide range of pH tolerance (3 to 9). In summary, our study indicates that isolated strain Pseudomonas PY-4B is a safe and applicable strain and has the ability to effectively degrade the ANFs (phytic acid, glycinin, and ß-conglycinin) in SBM by fermentation.
Subject(s)
6-Phytase , 6-Phytase/metabolism , Peptide Hydrolases/metabolism , Fermentation , Phytic Acid/metabolism , Flour , Glycine max , Endopeptidases/metabolism , Animal Feed/analysisABSTRACT
The dysregulated expression of cyclin genes can lead to the uncontrolled proliferation of cancer cells. Histone demethylase Jumonji-C domain-containing protein 5 (KDM8, JMJD5) and cyclin A1 (CCNA1) are pivotal in cell cycle progression. A promising candidate for augmenting cancer treatment is Allyl isothiocyanate (AITC), a natural dietary chemotherapeutic and epigenetic modulator. This study aimed to investigate AITC's impact on the KDM8/CCNA1 axis to elucidate its role in oral squamous cell carcinoma (OSCC) tumorigenesis. The expression of KDM8 and CCNA1 was assessed using a tissue microarray (TMA) immunohistochemistry (IHC) assay. In vitro experiments with OSCC cell lines and in vivo experiments with patient-derived tumor xenograft (PDTX) and SAS subcutaneous xenograft tumor models were conducted to explore AITC's effects on their expression and cell proliferation. The results showed elevated KDM8 and CCNA1 levels in the OSCC patient samples. AITC exhibited inhibitory effects on OSCC tumor growth in vitro and in vivo. Additionally, AITC downregulated KDM8 and CCNA1 expression while inducing histone H3K36me2 expression in oral cancer cells. These findings underscore AITC's remarkable anticancer properties against oral cancer, highlighting its potential as a therapeutic option for oral cancer treatment by disrupting the cell cycle by targeting the KDM8/CCNA1 axis.
ABSTRACT
Adenosine monophosphate-activated protein kinase (AMPK) plays pivotal roles in metabolic diseases including type 2 diabetes. However, the specific role of AMPK for orthodontic tooth movement in type 2 diabetes is unclear. In this study, a diabetic rat model was established through dietary manipulation and streptozocin injection. Examinations were conducted to select qualified type 2 diabetic rats. Then, an orthodontic device was applied to these rats for 0, 3, 7, or 14 days. The distance of orthodontic tooth movement and parameters of alveolar bone were analyzed by micro-computed tomography. Periodontal osteoclastic activity, inflammatory status, and AMPK activity were measured via histological analyses. Next, we repeated the establishment of diabetic rats to investigate whether change of AMPK activity was associated with orthodontic tooth movement under type 2 diabetes. The results showed that diabetic rats exhibited an exacerbated alveolar bone resorption, overactive inflammation, and decreased periodontal AMPK activity during orthodontic tooth movement. Injection of the AMPK agonist alleviated type 2 diabetes-induced periodontal inflammation and alveolar bone resorption, thus normalizing distance of orthodontic tooth movement. Our study indicates that type 2 diabetes decreases periodontal AMPK activity, leading to excessive inflammation elevating osteoclast formation and alveolar bone resorption, which could be reversed by AMPK activation.
Subject(s)
Alveolar Bone Loss , Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Rats , Animals , Diabetes Mellitus, Type 2/complications , Tooth Movement Techniques/methods , X-Ray Microtomography , AMP-Activated Protein Kinases , Alveolar Bone Loss/diagnostic imaging , Inflammation , Periodontal LigamentABSTRACT
The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.
Subject(s)
Hedgehog Proteins , Neoplasms , Adult , Female , Pregnancy , Humans , Hedgehog Proteins/genetics , Homeostasis/genetics , Neoplasms/drug therapy , Neoplasms/genetics , Signal Transduction/genetics , Cell DifferentiationABSTRACT
Cyclic di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger that can be recognized by infected host cells and activate the immunoinflammatory response. The purpose of this study is to demonstrate the effect of c-di-AMP on the differentiation of human periodontal ligament stem cells (hPDLSCs) and its underlying mechanisms. In the present study, we find that the gingival crevicular fluid (GCF) of patients with chronic periodontitis has a higher expression level of c-di-AMP than that of healthy people. In vitro, c-di-AMP influences the differentiation of hPDLSCs by upregulating Toll-like receptors (TLRs); specifically, it inhibits osteogenic differentiation by activating NF-κB and ERK/MAPK and promotes adipogenic differentiation through the NF-κB and p38/MAPK signaling pathways. Inhibitors of TLRs or activated pathways reduce the changes induced by c-di-AMP. Our results establish the potential correlation among bacterial c-di-AMP, periodontal tissue homeostasis and chronic periodontitis pathogenesis.
Subject(s)
Chronic Periodontitis , NF-kappa B , Humans , NF-kappa B/metabolism , Periodontal Ligament/metabolism , Osteogenesis , Chronic Periodontitis/metabolism , Cell Differentiation , Stem Cells/metabolism , Toll-Like Receptors/metabolism , Adenosine Monophosphate/metabolism , Cells, CulturedABSTRACT
The DEAD-box proteins, one family of RNA-binding proteins (RBPs), participate in post-transcriptional regulation of gene expression with multiple aspects. Among them, DDX6 is an essential component of the cytoplasmic RNA processing body (P-body) and is involved in translational repression, miRNA-meditated gene silencing, and RNA decay. In addition to the cytoplasmic function, DDX6 is also present in the nucleus, but the nuclear function remains unknown. To decipher the potential role of DDX6 in the nucleus, we performed mass spectrometry analysis of immunoprecipitated DDX6 from a HeLa nuclear extract. We found that adenosine deaminases that act on RNA 1 (ADAR1) interact with DDX6 in the nucleus. Utilizing our newly developed dual-fluorescence reporter assay, we elucidated the DDX6 function as negative regulators in cellular ADAR1p110 and ADAR2. In addition, depletion of DDX6 and ADARs results in the opposite effect on facilitation of RA-induced differentiation of neuronal lineage cells. Our data suggest the impact of DDX6 in regulation of the cellular RNA editing level, thus contributing to differentiation in the neuronal cell model.
Subject(s)
DEAD-box RNA Helicases , MicroRNAs , Humans , DEAD-box RNA Helicases/metabolism , Proto-Oncogene Proteins/genetics , MicroRNAs/genetics , Gene Expression Regulation , Cell Differentiation , Adenosine Deaminase/metabolismABSTRACT
Molecules based on benzimidazolone-dioxazine are known as blue/violet pigments and have been commercialized for decades. However, unfavorable solubility limits the application of these structures as building blocks of conjugated polymers despite their low band gaps. Herein, a series of donor-acceptor conjugated polymers containing soluble benzimidazolone-dioxazine structures as the acceptors and oligothiophene as donors are synthesized and investigated. With increasing numbers of thiophene rings, the steric hindrance diminishes and high molecular weight polymers can be achieved, leading to an improved performance in organic field effect transistor devices. The hole mobility of polymers with three to six thiophene units is in the order of 10-1 cm2 V-1 s -1 . Among all the polymers, polymer P3 with three thiophene units between benzimidazolone-dioxazine structures shows the best hole mobility of 0.4 cm2 V-1 s -1 . Grazing-incidence wide-angle X-ray scattering results reveal that the high mobility of organic field-effect transistors (OFETs) can be accredited by matched donor-acceptor packing in the solid thin films.
Subject(s)
Bandages , Benzimidazoles , Polymers , ThiophenesABSTRACT
The shapeshifting behavior for synthetic matters was found at either the molecular or supramolecular level, but the connection between shapeshifting at the two hierarchical levels remains missing. In this study, an 8-arm star giant molecule, NPOSS, was synthesized to connect the molecular and supramolecular shapeshifting. Controlling the conditions of bulk self-assembly allowed us to bring NPOSS into three different Ostwald's stages of nucleation. The high conformational flexibility of NPOSS facilitates molecular shapeshifting and allows NPOSS to take the discotic, rod-like and star-like geometries in different Ostwald's stages. Simultaneous changes in the supramolecular scaffolds were observed as the discotic, rod-like and star-like NPOSS molecules self-assembled into the supramolecular scaffolds of 1D columns, 2D lamellae, and 3D networks, respectively. These changes in the hierarchical structures also affect the CO2 affinity of NPOSS. Therefore, the connection between the molecular/supramolecular shapeshifting and the structure-driven property changes of NPOSS were established by taking advantage of the high conformational freedom of the 8-arm star giant molecule and its diverse self-assembly pathways leading to the different Ostwald's stages.
Subject(s)
Molecular ConformationABSTRACT
The nucleoside antibiotic, toyocamycin (TM) exhibits excellent potent activity against several phytopathogenic fungi. Despite its importance, little is known about key factors regulating TM biosynthesis and morphological differentiation in Streptomyces diastatochromogenes 1628. Based on proteomics data obtained from the analysis between wild-type (WT) S. diastatochromogenes 1628 strain and mutant strain 1628-T62 having a low yield of TM, we observed that the differentially expressed protein, X0P338, which was proposed to be a regulator of the GntR-family, exhibited a higher expression level in S. diastatochromogenes 1628. Therefore, in this study, to explore whether protein X0P338 was involved in morphological differentiation and biosynthesis of secondary metabolites, especially TM, the gene called the gntRsd -encoding protein X0P338 was cloned and overexpressed in WT strain 1628 and mutant strain 1628-T62, respectively. The results indicated that the overexpression of gntRsd enhanced TM production in both strain 1628 (120.6 mg/L vs. 306.6 mg/L) and strain 1628-T62 (15.6 mg/L vs. 258.9 mg/L). Besides, the overexpression of gntRsd had positive and negative effects on morphological differentiation in strain 1628 and strain 1628-T62, respectively. The results also showed opposite effects on tetraene macrolide production during the overexpression of gntRsd in strain 1628 and strain 1628-T62. Moreover, transcription levels of genes involved in morphological differentiation and secondary metabolites production were affected by the overexpression of gntRsd gene, both in strain 1628 and strain 1628-T62. These results confirm that X0P338 as a GntR-type pleiotropic regulator that regulates the morphological differentiation and biosynthesis of secondary metabolites, and especially has a positive effect on TM biosynthesis.
Subject(s)
Streptomyces , Toyocamycin , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Gene Expression Regulation, Bacterial , Streptomyces/genetics , Streptomyces/metabolism , Toyocamycin/metabolismABSTRACT
Giant shape amphiphiles (GSA) are giant molecules made with nano-building blocks that have distinct shapes. The incompatible packing behaviors of the nano-building blocks of GSA could create cavities within certain conformers of the GSA, but the host-guest chemistry of GSA has not been explored yet. In this study, POSS-PDI-POSS (PPP), which is made by connecting two nano-cubes, isobutyl-polyhedral oligomeric silsesquioxanes (POSS), to a conjugated π-conjugated core, perylene diimide (PDI), is demonstrated as a novel acyclic synthetic host. In its bent conformer, PPP shows a cavity next to its PDI core. Via forming host-guest complexes with π-conjugated guests such as pyrene and perylene, PPP is found to transform from the bent-conformer into the extended-conformer, creating the steric features to accommodate guest molecules. Subsequent thermal annealing of the host-guest complexes removes the π-conjugated guests and restores the bent conformation and photophysical properties of PPP, which verifies that PPP, as a novel acyclic host, is capable of dynamic host-guest assembly. Moreover, the results prove that cavities at the molecular level can be created by connecting nano-building blocks with distinct shapes. This finding may inspire developments in the host-guest chemistry of GSA and nanomaterial innovation.
ABSTRACT
Evolving synthetic molecules toward complex structures is a major goal in supramolecular chemistry. Increasing the number of clips in a unimolecular multi-clip (UMC), although vital to elevate the complexity of supramolecular architectures, often prevents the UMC from forming host-guest complexes in the bulk phase. To overcome this difficulty, adaptive chemistry was applied to develop a novel adaptive unimolecular quaternary clip (Q-clip). The Q-clip is intrinsically amorphous, but self-organizes with exclusively 4 eq. of allosteric activators (NDI) to form the Q-clip : NDI4 complexes and a supramolecular lamellar structure in the bulk. The adaptive assembly is fast and allows us to locate the adaptive assembly area of Q-clip : NDI4 complexes in the amorphous Q-clip film. Our results provide new insights into the design of adaptive UMCs for the evolution toward complex structures and supramolecular functional materials.
ABSTRACT
Cartilage-derived pluripotent cells reside in hyaline cartilage and fibrocartilage. These cells have the potential for multidirectional differentiation; can undergo adipogenesis, osteogenesis, and chondrogenesis; and have been classified as mesenchymal stem cells (MSCs) conforming to the minimal criteria of the International Society for Cellular Therapy. Cartilage tissue is prone to injury and is difficult to repair. As cartilage-derived pluripotent cells are the closest cell source to cartilage tissue, they are expected to have the strongest ability to differentiate into cartilage compared to other MSCs. This review focuses on the organizational distribution, expression, and function of cartilage-derived pluripotent cells in joint development and repair to help explore the therapeutic potential of in situ cartilage-derived pluripotent cells for joint cartilage repair.
Subject(s)
Cartilage, Articular , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Cell Differentiation , Chondrogenesis , OsteogenesisABSTRACT
BACKGROUND: Hospice care has been part of the Taiwan health-care system for 20 years. Detailed information on the place of death for terminal cancer patients is lacking. Impending death discharge (IDD) is unique in Taiwan, and our study aims to compare IDD with in-hospice death among terminal cancer patients under hospice care. METHODS: This retrospective study used claims data of decedents of cancer from the National Health Insurance Research Database of Taiwan from 2007 to 2010. RESULTS: Of the 22,720 cancer decedents enrolled, 6316 had claims data marked with IDD and 16,404 with in-hospice death. Those with IDD were older; had a shorter hospice stay; and higher rates of gastrointestinal, peritoneal, and pulmonary cancers. The mean daily health-care expenditure was higher in those with IDD, however, the total expenditure of terminal hospice admission was lower than those dying in hospices. Patients who were treated at public hospitals had a higher rate of in-hospice death than those treated at private hospitals. Patients with IDD were positively correlated with increasing age and shorter hospice stay. Patients with IDD were positively correlated with private hospitals, especially religious corporation-based hospitals. Male sex, oropharyngeal cancer, bone/connective/breast cancers, and secondary/metastatic cancers were negatively correlated with IDD. CONCLUSION: Patients with IDD have characteristics distinct from those dying in hospices. Advanced age and short hospice stays were common in those with IDD, and in-depth investigations were needed. As a unique predying process in Taiwan, relevant health-care issues regarding IDD are warranted for further investigations.
Subject(s)
Hospice Care , Neoplasms/therapy , Patient Discharge , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies , TaiwanABSTRACT
New silicon based anodic materials in lithium ion batteries (Si-based LIBs) have been developed worldwide to overcome capacity decay during the lithiation/delithiation process. In this study, a composite of Si nanoparticles coated with 5-sulfoisophthalic acid (SPA) doped polyaniline (core/shell SiNPs@PANi/SPA) was prepared and applied as an anode material for LIB applications. The detailed structure of the core/shell SiNPs@PANi/SPA composite was characterized using high-resolution scanning electron microscopy before and after charging/discharging. The electrochemical measurements showed that the SiNPs@PANi/SPA anode exhibited a high capacity of 925 mA h g(-1) and high coulombic efficiency (99.6%) after long-term cycling (1000 cycles). Overall results indicated that the SPA doped polyaniline served as a conductive matrix to improve electrical contact and to provide an adhesive force in Si-based LIBs. Our approach opens a route for the design of efficient silicon nanocomposites for LIB applications.
ABSTRACT
INTRODUCTION: Gingiva-derived mesenchymal stem cells (GMSCs) have recently been harvested and applied for rebuilding lost periodontal tissue. Enamel matrix derivative (EMD) has been used for periodontal regeneration and the formation of new cementum with inserting collagen fibers; however, alveolar bone formation is minimal. Recently, EMD has been shown to enhance the proliferation and mineralization of human bone marrow mesenchymal stem cells. Because the gingival flap is the major component to cover the surgical wound, the effects of EMD on the proliferation and mineralization of GMSCs were evaluated in the present study. METHODS: After single cell suspension, the GMSCs were isolated from the connective tissues of human gingiva. The colony forming unit assay of the isolated GMSCs was measured. The expression of stem cell markers was examined by flow cytometry. The cellular telomerase activity was identified by polymerase chain reaction (PCR). The osteogenic, adipogenic and neural differentiations of the GMSCs were further examined. The cell proliferation was determined by MTS assay, while the expression of mRNA and protein for mineralization (including core binding factor alpha, cbfα-1; alkaline phosphatase, ALP; and osteocalcin, OC; ameloblastin, AMBN) were analyzed by real time-PCR, enzyme activity and confocal laser scanning microscopy. RESULTS: The cell colonies could be easily identified and the colony forming rates and the telomerase activities increased after passaging. The GMSCs expressed high levels of surface markers for CD73, CD90, and CD105, but showed low expression of STRO-1. Osteogenic, adipogenic and neural differentiations were successfully induced. The proliferation of GMSCs was increased after EMD treatment. ALP mRNA was significantly augmented by treating with EMD for 3 hours, whereas AMBN mRNA was significantly increased at 6 hours after EMD treatment. The gene expression of OC was enhanced at the dose of 100 µg/ml EMD at day 3. Increased protein expression for cbfα-1 at day 3, for ALP at day 5 and 7, and for OC at week 4 after the EMD treatments were observed. CONCLUSIONS: Human GMSCs could be successfully isolated and identified. EMD treatments not only induced the proliferation of GMSCs but also enhanced their osteogenic differentiation after induction.
Subject(s)
Bone and Bones/cytology , Dental Enamel/metabolism , Gingiva/cytology , Mesenchymal Stem Cells/cytology , Osteogenesis/drug effects , Bone and Bones/metabolism , Cell Differentiation/physiology , Cell Proliferation/physiology , Gingiva/metabolism , Humans , Mesenchymal Stem Cells/metabolismABSTRACT
In this paper, we propose a novel possibilistic fuzzy matching strategy with invariant properties, which can provide a robust and effective matching scheme for two sets of iris feature points. In addition, the nonlinear normalization model is adopted to provide more accurate position before matching. Moreover, an effective iris segmentation method is proposed to refine the detected inner and outer boundaries to smooth curves. For feature extraction, the Gabor filters are adopted to detect the local feature points from the segmented iris image in the Cartesian coordinate system and to generate a rotation-invariant descriptor for each detected point. After that, the proposed matching algorithm is used to compute a similarity score for two sets of feature points from a pair of iris images. The experimental results show that the performance of our system is better than those of the systems based on the local features and is comparable to those of the typical systems.