Collagen-based materials, renowned for their biocompatibility and minimal immunogenicity, serve as exemplary substrates in a myriad of biomedical applications. Collagen-based micro/nanogels, in particular, are valued for their increased surface area, tunable degradation rates, and ability to facilitate targeted drug delivery, making them instrumental in advanced therapeutics and tissue engineering endeavors. Although extensive reviews on micro/nanogels exist, they tend to cover a wide range of biomaterials and lack a specific focus on collagen-based materials. The current review offers an in-depth look into the manufacturing technologies, drug release mechanisms, and biomedical applications of collagen-based micro/nanogels to address this gap. First, we provide an overview of the synthetic strategies that allow the precise control of the size, shape, and mechanical strength of these collagen-based micro/nanogels by controlling the degree of cross-linking of the materials. These properties are crucial for their performance in biomedical applications. We then highlight the environmental responsiveness of these collagen-based micro/nanogels, particularly their sensitivity to enzymes and pH, which enables controlled drug release under various pathological conditions. The discussion then expands to include their applications in cancer therapy, antimicrobial treatments, bone tissue repair, and imaging diagnosis, emphasizing their versatility and potential in these critical areas. The challenges and future perspectives of collagen-based micro/nanogels in the field are discussed at the end of the review, with an emphasis on the translation to clinical practice. This comprehensive review serves as a valuable resource for researchers, clinicians, and scientists alike, providing insights into the current state and future directions of collagen-based micro/nanogel research and development.
Collagen/chemistry* ; Drug Delivery Systems/methods* ; Humans ; Tissue Engineering/methods* ; Animals ; Biocompatible Materials/chemistry*

Objective To investigate the anti-inflammatory properties of bergaptenand its inhibition of bone resorption in the treatment of periodontitis,as well as its potential underlying mechanisms.Methods A total of 35 male Wistar rats were randomly di-vided into five groups(control group,model group,and low-,medium-,and high-dose bergapten groups,with 7 rats in each group).Except for the control group,periodontitis was induced in all other groups by orthodontic ligation of the bilateral maxillary first molars(M1)and feeding a high-sugar diet.After successful modeling,the control and model groups received gavage of isotonic saline,while the bergapten groups received gavage of 50,100,and 200 mg/kg bergapten,respectively,once daily for 4 consecutive weeks.Perio-dontal symptoms were observed,and GI,SBI grades,and PLI scores were recorded.Rats were sacrificed within 24 hours after the last administration,and their maxillae were immediately subjected to Micro-CT scanning to assess alveolar bone resorption.Histopathological changes in the periodontal tissues were observed using HE staining,and serum levels of pro-inflammatory cytokines(IL-6 and IL-1β)were measured by ELISA.Results Compared with the control group,the model group exhibited significantly higher levels of IL-6,IL-1β,GI,SBI grades,PLI scores,and CEJ-ABC distance,while bone volume to total volume ratio(BV/TV),trabec-ular number(Tb.N),and trabecular thickness(Tb.Th)were significantly reduced(P＜0.001).In comparison to the model group,the bergapten groups(with the exception of the low-dose group for IL-6)demonstrated reductions in IL-6,IL-1β levels,GI,SBI grades,PLI scores,and CEJ-ABC distance,with the medium-dose group showing the most pronounced effect(except for IL-6).Conclusion Bergapten can effectively prevent and treat periodontitis by inhibiting the secretion of IL-6 and IL-1β cytokines,achieving anti-inflam-matory effects and inhibiting bone resorption.

Objective To investigate the anti-inflammatory properties of bergaptenand its inhibition of bone resorption in the treatment of periodontitis,as well as its potential underlying mechanisms.Methods A total of 35 male Wistar rats were randomly di-vided into five groups(control group,model group,and low-,medium-,and high-dose bergapten groups,with 7 rats in each group).Except for the control group,periodontitis was induced in all other groups by orthodontic ligation of the bilateral maxillary first molars(M1)and feeding a high-sugar diet.After successful modeling,the control and model groups received gavage of isotonic saline,while the bergapten groups received gavage of 50,100,and 200 mg/kg bergapten,respectively,once daily for 4 consecutive weeks.Perio-dontal symptoms were observed,and GI,SBI grades,and PLI scores were recorded.Rats were sacrificed within 24 hours after the last administration,and their maxillae were immediately subjected to Micro-CT scanning to assess alveolar bone resorption.Histopathological changes in the periodontal tissues were observed using HE staining,and serum levels of pro-inflammatory cytokines(IL-6 and IL-1β)were measured by ELISA.Results Compared with the control group,the model group exhibited significantly higher levels of IL-6,IL-1β,GI,SBI grades,PLI scores,and CEJ-ABC distance,while bone volume to total volume ratio(BV/TV),trabec-ular number(Tb.N),and trabecular thickness(Tb.Th)were significantly reduced(P＜0.001).In comparison to the model group,the bergapten groups(with the exception of the low-dose group for IL-6)demonstrated reductions in IL-6,IL-1β levels,GI,SBI grades,PLI scores,and CEJ-ABC distance,with the medium-dose group showing the most pronounced effect(except for IL-6).Conclusion Bergapten can effectively prevent and treat periodontitis by inhibiting the secretion of IL-6 and IL-1β cytokines,achieving anti-inflam-matory effects and inhibiting bone resorption.

Objective To evaluate the clinical value of endoscopic retrograde pancreatic drainage ( ERPD) in patients with pancreatic fistula. Methods Data of 42 patients with pancreatic fistula, who were treated with ERPD at Changhai Hospital and Henan Provincial People's Hospital from June 2013 to September 2018,were collected. The pancreatic fistula curative rate, healing duration of pancreatic fistula, and the incidence of complications were analyzed. Results Among 42 patients with pancreatic fistula,there were 30 males(71. 4％) and 12 females(28. 6％) with mean age of 41. 5±12. 8 years old. Pancreatic duct stents of 37 cases ( 88. 1％) went across the fistula. The overall curative rate was 90. 5％( 38/42 ) . The median healing duration of pancreatic fistula was 32. 0 d (8-183 d). The healing time of pancreatic fistula after injury(19. 0±9. 9 d,t=3. 50,P=0. 002) and of pancreatic fistula after surgery(20. 3±10. 7 d,t=3. 35, P=0. 003) were shorter than that of pancreatic fistula after acute severe pancreatitis (60. 0±48. 6 d). The healing time of pancreatic fistula with pancreatic pseudocysts was longer than that of pancreatic fistula without pancreatic pseudocysts (65. 3±55. 4 d VS 32. 6±23. 6 d, t=2. 21,P=0. 040). There were no significant differences in pancreatic fistula curative rate, pancreatic healing duration and times of ERCP in pancreatic fistula at different position. Postoperative stent-related complications occurred in 2 patients ( 4. 8％) , and 1 patient (2. 4％) developed mild pancreatitis. Conclusion ERPD is an important treating method with good therapeutic effect and low complications for pancreatic fistula.

Objective To prepare a red blood cells based multifunctional nanoscaled drug delivery system,and to study its in vitro photothermal and photodynamic effects.Methods The indocyanine green (ICG)/doxorubicin (DOX) co-loaded nanoscaled red blood cells (DIRAs) were prepared using an extrusion method.The morphology,particle size,encapsulation efficiency,and stability were determined.The heating related change of particle size was studied using a size and potential tester.The in vitro photothermal effect was studied using an infrared imaging device.The uptake of DIRAs to 4T1 cells was studied using a CLSM examination.The in vitro photodynamic effect was studied using a fluorescence probe and CLSM examination.Results DIRAs were successfully prepared with a uniform and homogeneous size which was about (97.0±20.1) nm.The Zeta potential was about-21.6 mV and the encapsulation efficiency of ICG and DOX were 93.5％ and 95.2％,respectively.The DIRAs had excellent stability within 28 days.This nanoscaled drug delivery system had identical photothermal effect compared to free ICG.The cellular uptake of DOX was significantly improved after the laser irradiation and the photodynamic effect was enhanced.Conclusions The prepared DIRAs have regular shape,suitable particle size,high encapsulation efficiency and high photothermal conversion efficiency.DIRAs can improve the cellular uptake of DOX and enhance the photodynamic efficiency.This biomimetic muhifunctional nano-system could facilitate breast cancer treatment by combining PTT7PDT and chemotherapy.