1.Functionalized biomimetic mineralized collagen modified orthopedic implants
Wenhe XU ; Xiaobing LI ; Fang LIU
Chinese Journal of Tissue Engineering Research 2026;30(2):516-527
BACKGROUND:Mineralized collagen is the fundamental unit of bone structure and function and a major component of the extracellular matrix.Biomimetic methods have been developed to fabricate mineralized collagen with a natural bone nanostructure.Currently,mineralized collagen has been approved by regulatory authorities and applied clinically,playing a positive role in bone defect repair.OBJECTIVE:To present the integration strategies of bioactive factors with mineralized collagen,summarize schemes to enhance the osteogenic potential of mineralized collagen,emphasize the multifunctional coordination applications of mineralized collagen,and finally discuss current research focuses and future trends.METHODS:The authors searched for relevant literature in databases such as PubMed,Web of Science,Medline,WanFang,and CNKI,from 2009 to 2023,using keywords"mineralized collagen,biomimetic,functionalization,bioactive factors,osteogenesis,multi-functional coordination,bone tissue repair"in English and"mineralized collagen,biomimetic,functionalization"in Chinese.Out of 375 initially identified articles,57 were included for review after screening.RESULTS AND CONCLUSION:(1)Mineralized collagen,with its porous structure and large surface area,containing nano-hydroxyapatite,makes it an effective carrier for cells,various growth factors,and drugs.(2)Single or multiple bioactive factors can be efficiently and orderly released through different loading methods or combinations,achieving the multifunctionalization of mineralized collagen.The impact of physicochemical conditions on the bioactivity of factors and their effects on the degradability,hydroxylapatite crystal morphology,nanostructure,and content of mineralized collagen should be considered.Moreover,calcium ions in mineralized collagen can be substituted with various inorganic non-metal ions,enhancing its osteogenic,angiogenic,immunomodulatory,and anti-infective properties.(3)Ultimately,during in situ bone regeneration,functionalized mineralized collagen serves as a scaffold material,providing structural support for bone defects,and as a drug delivery system,continuously delivering various bioactive factors locally,playing roles in anti-infection,immunomodulation,promoting angiogenesis and osteogenesis,and repairing various complex bone defects.
2.Application of Onlay bone grafts from mandibular lateral oblique line in implant restoration of bone defects in upper anterior teeth
Shencong XU ; Zifei FANG ; Mingyi JI ; Chengrui XU ; Binhong LI ; Jiayu CAO ; Junfeng XU
Chinese Journal of Tissue Engineering Research 2026;30(4):841-848
BACKGROUND:With the development of oral implantology,implant restoration has gradually become the first choice of restoration after missing teeth,and bone augmentation procedures have led to the expansion of implant indications and the improvement of the success rate of implant restoration.However,the long-term stability of bone height,width and volume after bone augmentation surgery has been one of the clinical difficulties for oral implantologists.OBJECTIVE:To measure and analyze the bone width,height,and volume of different sites in the bone augmentation area at different time points using cone-beam CT and an automatic image alignment program.METHODS:Seventeen patients with severe bone defects in the upper anterior region who underwent Onlay bone block grafting in the external oblique region were recruited from the Department of Stomatology,Zhejiang Tongde Hospital.There were 10 males and 7 females,with a mean age of(45.88±12.47)years.The cone-beam CT scans of the patients' Onlay bone grafts were taken at five time points:preoperatively,immediately postoperatively,6 months postoperatively,immediately post implantation,and 6 months post implantation,and then were statistically analyzed for alveolar bone volume,width,and height in the bone augmentation area,as well as for the difference in the alveolar bone volume of the bone incremental area between patients of different sexes and age.RESULTS AND CONCLUSION:(1)The alveolar bone volume in the bone augmentation area was higher immediately and 6 months after bone grafting than before bone grafting(P<0.05)as well as was higher immediately after bone grafting than 6 months after bone grafting(P<0.05).The alveolar bone height in the bone augmentation area was higher immediately and 6 months after bone grafting than before bone grafting(P<0.05).The horizontal width of the alveolar bone at various sites in the bone augmentation area immediately and 6 months after bone grafting was higher than that before bone grafting(P<0.05).(2)There was no significant difference in the volume of bone graft resorption at various sites in the bone augmentation area between males and females immediately and 6 months after bone grafting(P>0.05).Pearson correlation analysis showed a positive correlation between age and the change in bone augmentation area volume immediately and 6 months after bone grafting,but the difference was not statistically significant(P>0.05).(3)Twenty-five dental implants with completed implant restorations functioned normally,and the survival rate of the implants was 100%.To conclude,Onlay bone graft implant restoration in the upper anterior region can significantly improve insufficient bone with favorable outcomes.However,there is some amount of bone resorption in the bone augmentation area at 6 months after Onlay bone grafting and it is necessary to open up the second surgical area.Clinicians should consider different bone augmentation procedures in accordance with the specific circumstances.
3.Effect and mechanism of peroxiredoxin 1 in microglial inflammation after spinal cord injury
Yongcheng YIN ; Xiangrui ZHAO ; Zhijie YANG ; Zheng LI ; Fang LI ; Bin NING
Chinese Journal of Tissue Engineering Research 2026;30(5):1106-1113
BACKGROUND:The inflammatory response of microglia is closely related to neuronal survival,regeneration,and functional recovery after spinal cord injury.Peroxiredoxin 1 is not only involved in the regulation of oxidative stress,but also has an important effect on cell proliferation,apoptosis,and inflammatory response.OBJECTIVE:To investigate the role and mechanism of peroxiredoxin 1 in the inflammatory response of microglia following spinal cord injury.METHODS:(1)Twelve female C57BL/6 mice were randomly divided into sham-operated(n=6)and spinal cord injury(n=6)groups.The sham-operated group was not modeled and acute spinal cord injury models were constructed in the spinal cord injury group using the modified Allen's method.Spinal cord tissue at the injured site was taken at 7 days after modeling and transcriptome sequencing was performed to identify differentially expressed genes.The expression of peroxiredoxin 1 in spinal cord tissues was verified using western blot and RT-qPCR.(2)Mouse microglia BV2 were divided into two groups:the control group was stimulated with lipopolysaccharide for 6 hours,and in the knockout group,lipopolysaccharide stimulation was applied for 6 hours at 24 hours after peroxiredoxin 1 was knocked down in the cells.RT-qPCR was performed to detect mRNA expression of peroxiredoxin 1,inflammatory factors(interleukin 1β,interleukin 6,inducible nitric oxide synthase,tumor necrosis factor α,C-C motif chemokine ligand 2,and C-X-C motif chemokine ligand 2),and western blot was performed to detect the expression of peroxiredoxin 1,inducible nitric oxide synthase,and reactive oxygen/mitogen-activated protein kinase signaling pathway proteins.Mouse microglia BV2 were treated in two groups:the control group was stimulated by hydrogen peroxide for 4 hours,and the knockout group was stimulated by hydrogen peroxide for 4 hours at 24 hours after knockdown of peroxiredoxin 1.The level of reactive oxygen species was detected by 2,7-dichlorodihydrofluorescein diacetate probe.RESULTS AND CONCLUSION:(1)Results from transcriptome sequencing,western blot and RT-qPCR confirmed that peroxiredoxin 1 expression levels in mouse spinal cord tissues were significantly higher in the spinal cord injury group than the sham-operated group(P<0.05).(2)Peroxiredoxin 1 knockdown in microglial cells led to decreased expression of peroxiredoxin 1 mRNA and protein(P<0.05),increased mRNA expression of interleukin 1β,interleukin 6,inducible nitric oxide synthase,tumor necrosis factor α,C-C motif chemokine ligand 2,and C-X-C motif chemokine ligand 2(P<0.05),increased protein expression of inducible nitric oxide synthase,P-P38,P-JNK and P-ERK proteins(P<0.05),and increased level of reactive oxygen species(P<0.05).To conclude,peroxiredoxin 1 regulates microglial inflammation by targeting the reactive oxygen species/mitogen-activated protein kinase signaling pathway.
4.Studies on glycosides from the n-butanol fraction of Aconitum tanguticum
Mengyuan ZHAO ; Siyang FANG ; anting LI ; Qien LI ; Ke PAN ; Zhiqi YIN
Journal of China Pharmaceutical University 2026;57(2):189-195
In order to investigate the chemical constituents of glycosides in Aconitum tanguticum (Maxim.) Stapf, column chromatographic techniques such as silica gel, ODS, Sephadex LH-20, and semi-preparative high performance liquid chromatography were used to afford eight glycosides from the n-butanol fraction of the 85% ethanol extract of Aconitum tanguticum. Based on the physicochemical properties and spectral data, these compounds were identified as N-4-O-(β-D-glucopyranosyl)-phenethylbenzamide (1), N-(2'-β-D-glucopyranosyl-5'-methoxysalicyl)-4-hydroxy-3-methoxyanthranilic acid methyl ester (2), N-(2'-β-D-glucopyranosyl-5'-hydroxysalicyl)-4-hydroxy-3-methoxyanthranilic acid methyl ester (3), salidroside (4), benzyl primeveroside (5), phenethanol-β-D-xylose-(1''→6')-β-D-glucopyranoside (6), 4-dihydroxyphenethoxy-8-O-β-D-[6-O-(4-O-β-D-glucopyranosyl)-feruloyl]-glucopyranoside (7), phenethanol-α-L-arabinopyranosyl-(1''→6')-β-D-glucopyranoside (8). Among them, compounds 1 and 2 were new compounds, and compounds 5,6,8 were isolated from Aconitum tanguticum for the first time.
5.Indobufen attenuates cerebral ischemia–reperfusion injury by inhibiting the NF-κB/Caspase-1/GSDMD pathway
Yiyin XU ; Dan XU ; Xue GOU ; Weirong FANG ; Yunman LI ; Hua SHAO ; Yongqing WANG
Journal of China Pharmaceutical University 2026;57(2):246-255
Indobufen is a new generation of antiplatelet agents and has been shown to have antithrombotic effects in animal models. However, its therapeutic potential and mechanisms against cerebral ischemia/reperfusion (I/R) injury remain unclear. In this study, we evaluated the in vivo neuroprotective effects of indobufen through both pretreatment and posttreatment regimens in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). In vitro, human umbilical vein endothelial cells (HUVECs) subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) were employed to investigate the relationship between indobufen and the pyroptosis-associated NF-κB/Caspase-1/GSDMD pathway. The pharmacodynamic tests revealed that indobufen ameliorated I/R injury by decreasing the level of thromboxane B2 (TXB2), infarct size, brain edema and neurological impairment in rats and rescuing cell pyroptosis in HUVECs. The underlying mechanisms were probably related to pyroptosis suppression by regulating the NF-κB/Caspase-1/GSDMD pathway. Overall, these studies indicate that indobufen exerts protective and therapeutic effects against I/R injury by pyroptosis suppression via downregulating NF-κB/Caspase-1/GSDMD pathway.
6.Association between screen behaviors with overweight and obesity among children and adolescents
Chinese Journal of School Health 2026;47(4):486-489
Objective:
To investigate the prevalence of overweight and obesity among children and adolescents in Yangzhou City, and its association with screen behaviors, so as to provide scientific evidence for weight management among students.
Methods:
In May 2025, an electronic questionnaire survey was conducted among children and adolescents in Yangzhou City. A total of 3 722 participants were selected from grades 4 to 12 in 18 primary and secondary schools (108 classes) by using stratified cluster random sampling. The Chi square test was used to compare the differences in the detection rates of overweight and obesity among children and adolescents with 5 types of screen behaviors (watching TV, playing electronic games, scrolling short videos, screen based learning, electronic socializing) in different time groups each day (never, >0~<2 h, ≥2 h). Multivariate Logistic regression analysis was performed to examine the associations of five types of screen behaviors, presence of electronic devices in the bedroom, and screen use during meals on the weight status of children and adolescents.
Results:
The prevalence of overweight and obesity among children and adolescents was 37.3%. For all five types of screen behaviors, the differences in the distribution of overweight and obesity detection rates among children and adolescents across the three time spent categories were statistically significant ( χ 2=30.76- 70.78 , all P <0.01). After adjusting for confounding factors, multivariate Logistic regression analysis revealed that frequent or always using screens during meals( OR =1.63, 95% CI =1.14~2.31), playing video games ( OR =1.28, 95% CI =1.11-1.48), browsing short videos ( OR =1.29, 95% CI=1.09-1.54), and screen based learning ( OR =1.26, 95% CI =1.10-1.44) were significantly associated with overweight and obesity among children and adolescents (all P <0.05).
Conclusions
Excessive screen use is positively correlated with the incidence of overweight and obesity in children and adolescents. Targeted interventions on screen behaviors among children and adolescents are therefore warranted.
7.Impact of social capital, adverse childhood experiences and depressive symptoms on suicidal behavior among vocational high school students
YU Bin, YAN Jingyan, CHEN Xinguang, GUO Yan, LI Fang, YAN Hong, XIAO Chenchang
Chinese Journal of School Health 2026;47(4):506-511
Objective:
To explore the nonlinear dynamic effects of social capital, adverse childhood experiences (ACEs) and depressive symptoms on suicidal behavior among vocational high school students, so as to provide theoretical basis and practical references for formulating suicide prevention strategies.
Methods:
A convenience sampling method was employed to include 668 students from a vocational high school from Wuhan in March 2023. Social capital was used as the asymmetry variable, while ACEs and depressive symptoms were used as bifurcation variables, a cusp catastrophe model was constructed to analyze the nonlinear changes in suicidal behavior among vocational high school students, and its fit was compared with linear and Logistic regression models.
Results:
Among students in the health vocational high school in Wuhan, only suicidal ideation accounted for 8.5%, only suicide attempt for 18.6%, neither accounted for 31.9%, and both for 41.0%. Gender, left behind experience, family economic status, parental parenting styles, depressive symptoms, social capital, and ACEs were all related factors influencing suicidal behavior among vocational high school students ( χ 2/H=19.03, 13.33, 21.11, 46.70, 144.38, 24.61, 118.77, all P <0.05). Violin plots showed a bimodal distribution of suicidal behavior, indicating nonlinear variation characteristics. The cusp catastrophe model results showed that social capital was negatively correlated with suicidal behavior, but the relationship was bifurcated by ACEs ( α social capital = -0.006 , β ACEs =0.075) and depressive symptoms ( α social capital =-0.013, β depressive =0.028) (all P <0.05). When both ACEs and depressive symptoms coexisted, the impact of ACEs was stronger ( β ACEs =0.077, β depressive =0.014) (both P <0.05). The cusp catastrophe model fitted ( R 2=0.886, 0.881, 0.882) better than the linear ( R 2=0.258, 0.219, 0.258) and Logistic regression models ( R 2= 0.242, 0.211 , 0.176). Gender stratified analysis results showed that bifurcation effect of ACEs was stronger in males than in females( β boys =0.224, β girls =0.086); in females, both ACEs and depressive symptoms had a bifurcation effect, with the former showing a stronger effect ( β ACEs =0.062, β depressive =0.015) (all P <0.05).
Conclusions
Suicidal behavior among vocational high school students exhibits nonlinear characteristics. Improving social capital to reducing ACEs and depressive symptoms may contribute to decreasing adolescent suicidal behaviors.
8.Species of sandflies and prevalence of Leishmania infections in sandflies in selected areas of northern and northwestern China
Yaqi HE ; Lei CUI ; Yi ZHANG ; Yuanyuan LI ; Limin YANG ; Yuan FANG ; Zhongqiu LI ; Zhengbin ZHOU
Chinese Journal of Schistosomiasis Control 2026;38(1):20-28
Objective To investigate the species of sandflies and the prevalence of Leishmania infections in sandflies from selected areas of northern and northwestern China, so as to provide insights into identification of leishmaniasis vectors and assessment of epidemiological trends of leishmaniasis in China. Methods Sandfly samples were collected from Mentougou District of Beijing Municipality, Xiangning County in Linfen City of Shanxi Province, Ejin Banner in Alxa League of Inner Mongolia Autonomous Region, and Payzawat County of Karamay District of Karamay City, Gaochang District of Turpan City in Xinjiang Uygur Autonomous Region from July 2023 to July 2024. Approximately 100 intact female sandfly samples were randomly selected from each site and the species of sandflies was identified according to morphological characteristics and molecular assays. Female sandflies originating from the same habitat were grouped into pools of 10 individuals. Leishmania infection was detected using polymerase chain reaction (PCR) assay targeting the internal transcribed spacer 1 (ITS-1) gene, and the prevalence of Leishmania infection was calculated in sandflies from different sampling sites using the minimum infection rate (MIR) method. In addition, positive amplicons were sequenced and subjected to phylogenetic analysis. Results A total of 6 155 sandflies were collected from different environments at sampling sites across the six aforementioned regions from July 2023 to July 2024. Phlebotomus chinensis (96.00%) was the dominant sandfly species in Mentougou District, Beijing Municipality, with a small proportion of Ph. sergenti (4.00%), and only Ph. chinensis was found in Xiangning County, Linfen City, Shanxi Province. Ph. wui was the only sandfly species detected in Ejin Banner, Alxa League, Inner Mongolia Autonomous Region, and Payzawat County, Kashgar City, Xinjiang Uygur Autonomous Region, and Ph. caucasicus (97.70%) was the dominant sandfly species in Karamay District, Karamay City, Xinjiang Uygur Autonomous Region, with a small proportion of Ph. wui (2.30%), while Ph. alexandri was the only species in Gaochang District, Turpan City, Xinjiang Uygur Autonomous Region. A total of 40, 60, 34, 18, 18, and 22 pools of sandfly samples were tested from Mentougou District in Beijing Municipality, Xiangning County in Linfen City of Shanxi Province, Ejin Banner in Alxa League of Inner Mongolia Autonomous Region, Payzawat County in Kashgar City, Karamay District in Karamay City, and Gaochang District in Turpan City of Xinjiang Uygur Autonomous Region, respectively. L. infantum was detected in Ph. chinensis samples from Mentougou District in Beijing Municipality, and Xiangning County of Linfen City in Shanxi Province, with MIR of 0.25% to 1.00%, and L. donovani was detected in Ph. wui from Ejin Banner in Alxa League of Inner Mongolia Autonomous Region, and Payzawat County in Kashgar City of Xinjiang Uygur Autonomous Region, with MIR of 0.56% to 0.88%; however, no Leishmania infection was detected in Ph. caucasicus from Karamay District in Karamay City or Ph. alexandri from Gaochang District in Turpan City of Xinjiang Uygur Autonomous Region. Phylogenetic analysis showed that the Leishmania ITS-1 gene sequences obtained from Mentougou District in Beijing Municipality and Xiangning County in Linfen City of Shanxi Province were clustered into the same clade with the reference sequences of L. infantum ITS-1 gene, while the Leishmania ITS-1 gene sequences obtained from Ejin Banner in Alxa League of Inner Mongolia Autonomous Region and Payzawat County in Kashgar City of Xinjiang Uygur Autonomous Region were clustered into the same clade with the reference sequences of L. donovani ITS-1 gene. Conclusions There are variations in sandfly species in selected areas of northern and northwestern China, and variations in the species of Leishmania infecting sandflies. Improved surveillance of sandfly vectors and targeted control strategies with adaptations to geographical features and leishmaniasis vectors are recommended.
9.Polypeptide-based Nanocarriers for Oral Targeted Delivery of CAR Genes to Pancreatic Cancer
Feng XIN ; Jian REN ; Zhao-Zhen LI ; Quan FANG ; Rui-Jing LIANG ; Lan-Lan LIU ; Lin-Tao CAI
Progress in Biochemistry and Biophysics 2026;53(2):431-441
ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.
10.Polypeptide-based Nanocarriers for Oral Targeted Delivery of CAR Genes to Pancreatic Cancer
Feng XIN ; Jian REN ; Zhao-Zhen LI ; Quan FANG ; Rui-Jing LIANG ; Lan-Lan LIU ; Lin-Tao CAI
Progress in Biochemistry and Biophysics 2026;53(2):431-441
ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.


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