1.Application of colloidal gold method and chemiluminescence method for detecting gonadotropins in morning urine to assess pubertal development status in children.
Xue-Qi ZHAO ; Wen-Li LU ; Wen-Ying LI ; Jun-Qi WANG ; Zhi-Ya DONG ; Yuan XIAO ; Xiao-Fei ZHANG ; Li JIANG ; Xiao-Yu MA
Chinese Journal of Contemporary Pediatrics 2025;27(2):199-204
OBJECTIVES:
To explore the application of the colloidal gold method and chemiluminescence method in detecting gonadotropin (Gn) in morning urine for assessing pubertal development status in children.
METHODS:
A total of 132 children diagnosed with central precocious puberty (CPP), early and fast puberty (EFP), and premature thelarche (PT) at Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from November 2021 to December 2022 were included, along with 685 healthy children who underwent routine health examinations at the hospital's pediatric health care department during the same period. All 132 patients underwent a gonadotropin-releasing hormone (GnRH) stimulation test. Both patients and healthy children had their urinary Gn levels measured using the colloidal gold method and chemiluminescence method, including levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The correlation between serum Gn and urinary Gn detected by the two methods, as well as the correlation between Tanner stages of healthy children and urinary Gn, was analyzed.
RESULTS:
Urine Gn levels detected by both the colloidal gold method and chemiluminescence method showed a positive correlation with serum LH baseline values, LH peak values, baseline LH/FSH ratios, and peak LH/FSH ratios (P<0.05). In healthy children, urinary LH levels detected by the chemiluminescence method gradually increased from Tanner stage Ⅰ to Ⅳ (P<0.05), while urinary FSH levels were lower in Tanner stage I than in stages Ⅱ, Ⅲ, and IV (P<0.05). Urinary LH levels detected by the colloidal gold method were lower in Tanner stage I compared to stages Ⅱ, Ⅲ, and IV, with the highest levels observed in Tanner stage Ⅳ (P<0.05). Additionally, urinary FSH levels in Tanner stage Ⅲ were higher than in stages Ⅰ and Ⅱ (P<0.05). The area under the receiver operating characteristic curve for evaluating Tanner stages I and II in healthy children using urinary LH and FSH levels by the chemiluminescence method and urinary LH levels by the colloidal gold method were 0.730, 0.699, and 0.783, respectively.
CONCLUSIONS
The colloidal gold method and chemiluminescence method for detecting Gn in morning urine show good correlation with serum Gn levels. As a non-invasive and convenient detection method, the colloidal gold method can serve as a useful tool for screening the onset of pubertal development in children.
Humans
;
Child
;
Male
;
Female
;
Gold Colloid
;
Luminescent Measurements/methods*
;
Gonadotropins/urine*
;
Puberty
;
Luteinizing Hormone/urine*
;
Child, Preschool
;
Adolescent
;
Follicle Stimulating Hormone/urine*
2.Cyclic fatigue resistance of nickel-titanium files made by Gold heat treatment in simulated S-shaped root canals at different temperatures.
Journal of Peking University(Health Sciences) 2025;57(1):136-141
OBJECTIVE:
To compare the cyclic fatigue resistance of nickel-titanium files made by 3 new heat treatment in simulated S-shaped root canals at different temperatures.
METHODS:
Gold heat-treated nickel-titanium files TruNatomy (25 mm, tip size 26#/0.04) and ProTaper Gold (25 mm, tip size 25#/0.08) were selected as the experimental group, M wire technique nickel-titanium file ProTaper Next (25 mm, tip size 25#/0.06) was selected as the control group. It was speculated that the Gold technique used in TruNatomy nickel-titanium file was R phase separation technique, which included a complete intermediate R-phase, increasing its flexibility. ProTaper Gold was a CM wire nickel-titanium file and the increased phase transformation temperature by heat treatment introduced martensite at room temperature, while it underwent gold heat treatment on the surface, generating an intermediate R phase during phase transformation, providing hyperelastic. ProTaper Next used M wire technique, M wire included austenite at room temperature, where heat mechanical processing introduced hardened martensite, which was incapable of participating phase transformation. Because of the lower elastic modulus of hardened martensite than austenite, the flexibility of the file was increased. Twenty instruments of each nickel-titanium file were submitted to the cyclic fatigue test by using a simulated canal with double curvatures at room tem-perature (24 ℃) and 65 ℃, 10 instruments of each nickel-titanium file were selected at each temperature (n=10). At the same temperature, the number of cyclic fatigue (NCF) and fragment length were analyzed by using One-Way analysis of variance at a significance level of P < 0.05. NCF and fragment length of the same nickel-titanium file at room temperature and 65 ℃ were compared by paired sample t test and the significance level was α=0.05. Fractured surfaces were analyzed by using scanning electron microscope.
RESULTS:
In double-curved canals, all the failure of the files due to cyclic fatigue was first seen in the apical curvature before the coronal curvature. At room temperature, in the apical curvature, NCF of TruNatomy was 344.4±96.6, ProTaper Gold was 175.0±56.1, ProTaper Next was 133.3±39.7, NCF of Tru Natomy was the highest (P < 0.05). In the coronal curvature, NCF of TruNatomy was 618.3± 75.3, ProTaper Gold was 327.5±111.8, ProTaper Next was 376.6±67.9, NCF of TruNatomy was also the highest (P < 0.05). There was no significant difference among the apical and coronal fragment length of the 3 nickel-titanium files (P>0.05). At 65 ℃, in the apical curvature, NCF of TruNatomy was 289.6±65.8, ProTaper Gold was 187.5±75.4, ProTaper Next was 103.0±38.5, NCF of TruNatomy was the highest (P < 0.05). In the coronal curvature, NCF of TruNatomy was 454.2±45.4, ProTaper Gold was 268.3±31.4, ProTaper Next was 283.8±31.7, NCF of TruNatomy was also the highest (P < 0.05). The apical fragment length of ProTaper Next was the highest (P < 0.05), and there was no significant difference among coronal fragment length of the 3 nickel-titanium files (P>0.05). Compared with room temperature, at 65 ℃, in the coronal curvature, NCF of TruNatomy decreased significantly (P < 0.05). The fractured surfaces of the three nickel-titanium files demonstrated typical cyclic fatigue.
CONCLUSION
Gold heat-treated nickel-titanium file had better cyclic fatigue resistance than M wire nickel-titanium file in S-shaped root canals.
Nickel/chemistry*
;
Titanium/chemistry*
;
Hot Temperature
;
Root Canal Preparation/methods*
;
Humans
;
Materials Testing
;
Gold/chemistry*
;
Dental Alloys/chemistry*
;
Stress, Mechanical
3.A rapid method for detecting prfA and hly toxin genes of Listeria monocytogenes using double nucleic acid colloidal gold strips.
Yan LIU ; Jianyu YANG ; Yujiao ZHOU ; Wenbo DING ; Xianyu ZHANG ; Linran GAO ; Beizhen PAN ; Jifei YANG ; Yundong ZHAO
Journal of Southern Medical University 2025;45(2):387-394
OBJECTIVES:
To detect prfA and hly toxin genes of Listeria monocytogenes using polymerase chain reaction (PCR) and colloidal gold technology.
METHODS:
L. monocytogenes DNA was extracted by boiling method. With prfA and hly of L. monocytogenes as the target genes, the 5' ends of upstream and downstream primers of prfA gene were labeled with 6-FAM and biotin, and the 5' ends of upstream and downstream primers of hly gene were labeled with digoxin and biotin, respectively, to establish the toxin gene detection method. Using cloning transformation, sequencing analysis, cloning of positive control products, the detection kid was developed and its specificity, sensitivity, reproducibility and stability were tested, followed by verification with sample testing.
RESULTS:
The concentration of L. monocytogenes DNA extracted by boiling method was 148.81±0.97 ng/μL, and the A260/A280 ratio ranged from 1.8 to 2.0. The PCR products showed a 100% homology with the gene sequences in GenBank database after cloning, transformation and sequencing. The colloidal gold strip yielded positive results only for L. monocytogenes samples without cross-reactions with Staphylococcus aureus, Escherichia coli or Bacillus cereus, and its minimum detection limit was 10-2 ng/μL, demonstrating a 10-fold greater sensitivity of the test than agarose gel electrophoresis. The test also showed good reproducibility of the results when performed by different operators with good stability of the test strips after storage for 6 to 12 months. The test results showed that this kit could accurately and quickly detect L.monocytogenes in the test samples.
CONCLUSIONS
The detection kit developed in this study can simultaneously detect prfA and hly toxin genes of L. monocytogenes with good specificity, sensitivity, reproducibility and stability for use in food safety inspection.
Listeria monocytogenes/isolation & purification*
;
Gold Colloid
;
Bacterial Toxins/genetics*
;
Polymerase Chain Reaction/methods*
;
Hemolysin Proteins/genetics*
;
Bacterial Proteins/genetics*
;
DNA, Bacterial/genetics*
;
Food Microbiology
;
Heat-Shock Proteins
4.Tongue squamous cell carcinoma-targeting Au-HN-1 nanosystem for CT imaging and photothermal therapy.
Ming HAO ; Xingchen LI ; Xinxin ZHANG ; Boqiang TAO ; He SHI ; Jianing WU ; Yuyang LI ; Xiang LI ; Shuangji LI ; Han WU ; Jingcheng XIANG ; Dongxu WANG ; Weiwei LIU ; Guoqing WANG
International Journal of Oral Science 2025;17(1):9-9
Tongue squamous cell carcinoma (TSCC) is a prevalent malignancy that afflicts the head and neck area and presents a high incidence of metastasis and invasion. Accurate diagnosis and effective treatment are essential for enhancing the quality of life and the survival rates of TSCC patients. The current treatment modalities for TSCC frequently suffer from a lack of specificity and efficacy. Nanoparticles with diagnostic and photothermal therapeutic properties may offer a new approach for the targeted therapy of TSCC. However, inadequate accumulation of photosensitizers at the tumor site diminishes the efficacy of photothermal therapy (PTT). This study modified gold nanodots (AuNDs) with the TSCC-targeting peptide HN-1 to improve the selectivity and therapeutic effects of PTT. The Au-HN-1 nanosystem effectively targeted the TSCC cells and was rapidly delivered to the tumor tissues compared to the AuNDs. The enhanced accumulation of photosensitizing agents at tumor sites achieved significant PTT effects in a mouse model of TSCC. Moreover, owing to its stable long-term fluorescence and high X-ray attenuation coefficient, the Au-HN-1 nanosystem can be used for fluorescence and computed tomography imaging of TSCC, rendering it useful for early tumor detection and accurate delineation of surgical margins. In conclusion, Au-HN-1 represents a promising nanomedicine for imaging-based diagnosis and targeted PTT of TSCC.
Tongue Neoplasms/diagnostic imaging*
;
Carcinoma, Squamous Cell/diagnostic imaging*
;
Animals
;
Gold/chemistry*
;
Mice
;
Photothermal Therapy/methods*
;
Tomography, X-Ray Computed
;
Photosensitizing Agents
;
Metal Nanoparticles
;
Humans
;
Cell Line, Tumor
5.Role of Gold Nanorods Functionalized by Nucleic Acid Nanostructures Carrying Doxorubicin in Synergistic Anti-Cancer Therapy.
Hao WU ; Huang Shui MA ; Xing Han WU ; Qiang SUN ; Lin FENG ; Rui Fang JIANG ; Yan Hong LI ; Quan SHI
Biomedical and Environmental Sciences 2025;38(4):403-415
OBJECTIVE:
Cancer remains a significant global health challenge, necessitating the development of effective treatment approaches. Developing synergistic therapy can provide a highly promising strategy for anti-cancer treatment through combining the benefits of various mechanisms.
METHODS:
In this study, we developed a synergistic strategy for chemo-photothermal therapy by constructing nanocomposites using gold nanorods (GNRs) and tetrahedral framework nucleic acids (tFNA) loaded with the anti-tumor drug doxorubicin (DOX).
RESULTS:
Our in vitro studies have systematically clarified the anti-cancer behaviors of tFNA-DOX@GNR nanocomposites, characterized by their enhanced cellular uptake and proficient lysosomal escape capabilities. It was found that the key role of tFNA-DOX@GNR nanocomposites in tumor ablation is primarily due to their capacity to induce cytotoxicity in tumor cells via a photothermal effect, which generates instantaneous high temperatures. This mechanism introduces various responses in tumor cells, facilitated by the thermal effect and the integrated chemotherapeutic action of DOX. These reactions include the induction of endoplasmic reticulum stress, characterized by elevated reactive oxygen species levels, the promotion of apoptotic cell death, and the suppression of tumor cell proliferation.
CONCLUSION
This work exhibits the potential of synergistic therapy utilizing nanocomposites for cancer treatment and offers a promising avenue for future therapeutic strategies.
Doxorubicin/chemistry*
;
Gold/chemistry*
;
Nanotubes/chemistry*
;
Humans
;
Nanocomposites/chemistry*
;
Cell Line, Tumor
;
Nucleic Acids/chemistry*
;
Antibiotics, Antineoplastic/pharmacology*
;
Antineoplastic Agents/administration & dosage*
6.Remodeling of tumor stroma combined with photothermal therapy in the treatment of triple-negative breast cancer.
Jie ZHANG ; Yang LI ; Yu Xia TANG ; Fei Yun WU ; Shou Ju WANG
Chinese Journal of Oncology 2023;45(11):926-933
Objective: Polyethylene glycol-modified gold nanostar particles (GNS-PEG) were constructed to investigate whether the degradation of extracellular matrix in triple-negative breast cancer could improve the tumor delivery of GNS-PEG and enhance the efficacy of photothermal therapy. Methods: GNS-PEG were constructed and characterized for physicochemical properties as well as photothermal properties. At the cellular level, the cytotoxicity of halofuginone (HF) and the effect of photothermal therapy were detected. Mouse model of triple negative breast cancer was established by subcutaneous inoculation of 4T1 cells in BALB/c nude mice. Five injections of HF were given via tail vein (HF group), and tumor sections were stained with Masson stain and immunohistochemical staining for transforming growth factor β1 (TGFβ1), α-smooth muscle actin (α-SMA) and CD31 to observe the effect of tumor stromal degradation. Five injections of HF via tail vein followed by GNS-PEG (HF+ GNS-PEG group) were applied to determine the content of gold in tumor tissues by inductively coupled plasma mass spectrometry. The tumor sites of the mice in the GNS-PEG and HF+ GNS-PEG groups were irradiated with NIR laser and the temperature changes were recorded with an IR camera. The tumour growth and weight changes of mice in each group were observed. Ki-67 immunohistochemical staining, TdT-mediated dUTP nick-end labeling and HE staining were performed on tumor tissue sections from each group to observe tumor proliferation, apoptosis and necrosis. HE staining was performed on heart, liver, spleen, lung and kidney tissues from each group to observe the morphological changes of cells. Results: GNS-PEG nanoparticles showed a multi-branched structure with a particle size of 73.5±1.4 nm. The absorption peak of GNS was 810 nm, which is in the near infrared region. The photothermal conversion rate of GNS-PEG was up to 79.3%, and the photothermal effect could be controlled by the laser energy. HF has a concentration-dependent cytotoxicity, with a cell survival rate being as low as (22.8±2.6)% at HF concentration of up to 1 000 nmol/L. The photothermal effect of GNS-PEG was significant in killing tumor cells, with a cell survival rate of (32.7±5.2)% at the concentration of 25 pmol/L. The collagen area fraction, TGFβ1 integrated optical density and α-SMA integrated optical density in the tumor tissues of mice in the HF group were (2.1±0.2)%, 3.1±0.4 and 5.2±1.9, respectively, which were lower than those of the control group (all P<0.01), and the vessel diameter was 8.6±2.9 μm, which was higher than that of the control group (P<0.05). In the HF+ GNS-PEG group, the concentration of gold in tissues was 52.4 μg/g, higher than that in the GNS-PEG group (15.9 μg/g, P<0.05). After laser irradiation, the temperature of the tumor site in the HF+ GNS-PEG group was significantly higher than that in the GNS-PEG group. At the 4th minute, the temperatures of the tumor site in the GNS-PEG and HF+ GNS-PEG groups were 51.5 ℃ and 57.7 ℃ respectively; the tumor volume in the HF+ GNS-PEG group was effectively suppressed. The body weights of the mice in each group did not change significantly during the monitoring period. No significant abnormalities were observed in the main organs of the mice in the GNS-PEG group, but some hepatocytes in the HF and HF+ GNS-PEG groups showed edema and degeneration. Conclusion: The remodeling of extracellular matrix in triple-negative breast cancer could significantly improve the intratumoral delivery of GNS-PEG and thus achieve better photothermal therapy effect.
Humans
;
Animals
;
Mice
;
Phototherapy/methods*
;
Photothermal Therapy
;
Triple Negative Breast Neoplasms/pathology*
;
Hyperthermia, Induced/methods*
;
Mice, Nude
;
Gold/chemistry*
;
Cell Line, Tumor
7.Remodeling of tumor stroma combined with photothermal therapy in the treatment of triple-negative breast cancer.
Jie ZHANG ; Yang LI ; Yu Xia TANG ; Fei Yun WU ; Shou Ju WANG
Chinese Journal of Oncology 2023;45(11):926-933
Objective: Polyethylene glycol-modified gold nanostar particles (GNS-PEG) were constructed to investigate whether the degradation of extracellular matrix in triple-negative breast cancer could improve the tumor delivery of GNS-PEG and enhance the efficacy of photothermal therapy. Methods: GNS-PEG were constructed and characterized for physicochemical properties as well as photothermal properties. At the cellular level, the cytotoxicity of halofuginone (HF) and the effect of photothermal therapy were detected. Mouse model of triple negative breast cancer was established by subcutaneous inoculation of 4T1 cells in BALB/c nude mice. Five injections of HF were given via tail vein (HF group), and tumor sections were stained with Masson stain and immunohistochemical staining for transforming growth factor β1 (TGFβ1), α-smooth muscle actin (α-SMA) and CD31 to observe the effect of tumor stromal degradation. Five injections of HF via tail vein followed by GNS-PEG (HF+ GNS-PEG group) were applied to determine the content of gold in tumor tissues by inductively coupled plasma mass spectrometry. The tumor sites of the mice in the GNS-PEG and HF+ GNS-PEG groups were irradiated with NIR laser and the temperature changes were recorded with an IR camera. The tumour growth and weight changes of mice in each group were observed. Ki-67 immunohistochemical staining, TdT-mediated dUTP nick-end labeling and HE staining were performed on tumor tissue sections from each group to observe tumor proliferation, apoptosis and necrosis. HE staining was performed on heart, liver, spleen, lung and kidney tissues from each group to observe the morphological changes of cells. Results: GNS-PEG nanoparticles showed a multi-branched structure with a particle size of 73.5±1.4 nm. The absorption peak of GNS was 810 nm, which is in the near infrared region. The photothermal conversion rate of GNS-PEG was up to 79.3%, and the photothermal effect could be controlled by the laser energy. HF has a concentration-dependent cytotoxicity, with a cell survival rate being as low as (22.8±2.6)% at HF concentration of up to 1 000 nmol/L. The photothermal effect of GNS-PEG was significant in killing tumor cells, with a cell survival rate of (32.7±5.2)% at the concentration of 25 pmol/L. The collagen area fraction, TGFβ1 integrated optical density and α-SMA integrated optical density in the tumor tissues of mice in the HF group were (2.1±0.2)%, 3.1±0.4 and 5.2±1.9, respectively, which were lower than those of the control group (all P<0.01), and the vessel diameter was 8.6±2.9 μm, which was higher than that of the control group (P<0.05). In the HF+ GNS-PEG group, the concentration of gold in tissues was 52.4 μg/g, higher than that in the GNS-PEG group (15.9 μg/g, P<0.05). After laser irradiation, the temperature of the tumor site in the HF+ GNS-PEG group was significantly higher than that in the GNS-PEG group. At the 4th minute, the temperatures of the tumor site in the GNS-PEG and HF+ GNS-PEG groups were 51.5 ℃ and 57.7 ℃ respectively; the tumor volume in the HF+ GNS-PEG group was effectively suppressed. The body weights of the mice in each group did not change significantly during the monitoring period. No significant abnormalities were observed in the main organs of the mice in the GNS-PEG group, but some hepatocytes in the HF and HF+ GNS-PEG groups showed edema and degeneration. Conclusion: The remodeling of extracellular matrix in triple-negative breast cancer could significantly improve the intratumoral delivery of GNS-PEG and thus achieve better photothermal therapy effect.
Humans
;
Animals
;
Mice
;
Phototherapy/methods*
;
Photothermal Therapy
;
Triple Negative Breast Neoplasms/pathology*
;
Hyperthermia, Induced/methods*
;
Mice, Nude
;
Gold/chemistry*
;
Cell Line, Tumor
8.Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures.
Jin Hua ZHANG ; Jie PAN ; Zhi Peng SUN ; Xiao WANG
Journal of Peking University(Health Sciences) 2023;55(2):333-338
OBJECTIVE:
To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF).
METHODS:
A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists.
RESULTS:
The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001).
CONCLUSION
Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.
Animals
;
Cone-Beam Computed Tomography/methods*
;
Gold
;
Gutta-Percha
;
Palladium
;
Swine
;
Titanium
;
Tooth Fractures/diagnostic imaging*
;
Tooth Root/injuries*
;
Reproducibility of Results
9.A novel method for detecting circulating tumor cells immunity based on micro-nano technique.
Shuting LI ; Shufen JIAO ; Yu LI ; Yujuan WU ; Rongyun ZHAI ; Zhe WANG ; Jing CHENG ; Weiying ZHANG ; Yali BEN
Chinese Journal of Biotechnology 2023;39(9):3849-3862
This study was to develop a new method for detecting circulating tumor cells (CTCs) with high sensitivity and specificity, therefore to detect the colorectal cancer as early as possible for improving the detection rate of the disease. To this end, we prepared some micro-column structure microchips modified with graphite oxide-streptavidin (GO-SA) on the surface of microchips, further coupled with a broad-spectrum primary antibody (antibody1, Ab1), anti-epithelial cell adhesion molecule (anti-EpCAM) monoclonal antibody to capture CTCs. Besides, carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were coupled with colorectal cancer related antibody as specific antibody 2 (Ab2) to prepare complex. The sandwich structure consisting of Ab1-CTCs-Ab2 was constructed by the microchip for capturing CTCs. And the electrochemical workstation was used to detect and verify its high sensitivity and specificity. Results showed that the combination of immunosensor and micro-nano technology has greatly improved the detection sensitivity and specificity of the immunosensor. And we also verified the feasibility of the immunosensor for clinical blood sample detection, and successfully recognitized detection and quantization of CTCs in peripheral blood of colorectal cancer patients by this immunosensor. In conclusion, the super sandwich immunosensor based on micro-nano technology provides a new way for the detection of CTCs, which has potential application value in clinical diagnosis and real-time monitoring of disease.
Humans
;
Nanotubes, Carbon/chemistry*
;
Neoplastic Cells, Circulating/pathology*
;
Biosensing Techniques
;
Immunoassay/methods*
;
Antibodies
;
Colorectal Neoplasms/diagnosis*
;
Electrochemical Techniques/methods*
;
Gold/chemistry*
10.Droplet freeze-thawing system based on solid surface vitrification and laser rewarming.
Wenxin ZHU ; Ping'an PAN ; Yonghua HUANG ; Wei CHEN ; Sha HAN ; Zheng LI ; Jinsheng CHENG
Journal of Biomedical Engineering 2023;40(5):973-981
Ultra-rapid cooling and rewarming rate is a critical technical approach to achieve ice-free cells during the freezing and melting process. A set of ultra-rapid solid surface freeze-thaw visualization system was developed based on a sapphire flim, and experiments on droplet freeze-thaw were carried out under different cryoprotectant components, volumes and laser energies. The results showed that the cooling rate of 1 μL mixed cryoprotectant [1.5 mol/L propylene glycol (PG) + 1.5 mol/L ethylene glycol (EG) + 0.5 mol/L trehalose (TRE)] could be 9.2×10 3 °C/min. The volume range of 1-8 μL droplets could be vitrified. After comparing the proportions of multiple cryoprotectants, the combination of equal proportion mixed permeability protectant and trehalose had the best vitrification freezing effect and more uniform crystallization characteristics. During the rewarming operation, the heating curve of glassy droplets containing gold nanoparticles was measured for the first time under the action of 400-1 200 W laser power, and the rewarming rate was up to the order of 10 6 °C/min. According to the droplet images of different power rewarming processes, the laser power range for ice-free rewarming with micron-level resolution was clarified to be 1 400-1 600 W. The work of this paper simultaneously realizes the ultra-high-speed temperature ramp-up, transient visual observation and temperature measurement of droplets, providing technical means for judging the ice free droplets during the freeze-thaw process. It is conducive to promoting the development of ultra-rapid freeze-thaw technology for biological cells and tissues.
Freezing
;
Vitrification
;
Cryopreservation/methods*
;
Trehalose
;
Gold
;
Rewarming
;
Metal Nanoparticles
;
Cryoprotective Agents
;
Lasers

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