Three-dimensional (3D) printing technique has been improving the industrial process from uniform pipeline production procedure in manufacture into individualized production with distributed network. 3D printing technique also provokes these changes in the field of medicine, especially in orthopedics, stomatology and radiology. The role of 3D printing technique has been increasingly highlighted in tumor radiotherapy. Current studies and application mainly focus on personalized tissue compensato (bolus), brachytherapy (high-dose post-loading and particle implantation therapy), 3D printing personalized phantom and individualized fixtures, etc. In this article, research progresses on the application of 3D printing technique in radiotherapy at home and abroad were reviewed.

Background Dimethyl sulfoxide(DMSO) is a commonly used adjuvant to promote testing drug solubility to prepare multi-levels testing drug concentrations.DMSO is cell type-dependent cytotoxic and its toxicity can interfere the testing drug evaluation.Determining its safe concentration on commonly used cell types is important for ocular drug development.Objective This study was to determine the minimal toxic concentration of DMSO for in vitro ocular cell lines in a simulated drug screening setting.Methods Retinal pigment epithelial (RPE) cells were isolated from one pigmented rabbit and primarily cultured.Human RPE cell strain (ARPE19),scleral fibroblasts line (S75-Fron),human Müller cell line (MIO-M1),human lens epithelial cell line (HLEC),human choroidal melanoma cell line (OCM-1),human umbilical endothelial cell (HUVEC) and human HeLa cell line (HELA) were cultured.Different concentrations of DMSO (1.6％,1.0％,0.8％,0.4％,0.2％ and 0.1％) were prepared with 160 μl DMSO solution and 9.84 ml RPMI1640 (or DMEM/F12 or DMEM) containing 2％ fetal bovine serum.Different concentrations of DMSO were added in medium for 96 hours,and the and viability (absorbance) of the cells was detected using MTS to evaluate the cytotoxicity of DMSO.Results Rabbit primary RPE cells showed the yellow-green fluorescence for cytokeratin(CK) and HMB45 red fluorescence for S100.The viability of the cells was gradually declined as the increase of DMSO dose,showing significant differences in ARPE19,S75-Fron,HLEC,OCM-1,HUVEC and primary RPE cells (all at P＜0.05),and when DMSO concentrations were ≥ 0.8％,the cell viabilities were significantly lower.But no significant difference was found in MIO-M1 cells among different doses of DMSO (F=0.830,P=0.547).The minimal toxic concentration of DMSO for ARPE19,HUVEC,HELA,HLEC,MIO-M1,OCM-1,primary RPE cells and S75-Fron was 0.8％,0.1％,0.8％,＞1.6％,＞1.6％,0.2％,0.2％,0.2％,respectively,and HUVEC was more sensitive to the cytotoxicity of DMSO (P=0.02),and MIO-M1 was the least sensitive to DMSO (P =0.39).The viability of HUVEC and primary RPE cells went down with the increase of DMSO dose,and S75-Fron viability started to decline in 0.1％ DMSO and then stabilize with the higher concentrations until 1.6％ DMSO at which the viability showed further decline.Conclusions The tolerability of ocular cells in vitro to DMSO varies depending on the cell types.The minimal toxic concentration ranged from 0.1％ to 1.6％.The result suggests that a concurrent DMSO control should be set up along with the testing compound.

Objective To apply 3D printing technology to fabricate patient-specific silicone tissue compensators for the chest wall and compare the advantages and clinical characteristics between conventional bolus and 3D-printed PLA materials. Methods The chest wall data of two breast cancer patients undergoing mastectomy were obtained based upon the CT images. A patient-specific 3D printing silicone rubber bolus (3D-SRB) was designed and fabricated. The conformability of 3D-SRB,3D-PLA and conventional bolus to the chest wall were validated. Ecipse8. 6 planning system was adopted to statistically compare the dosimetric parameters of virtual plan with those after using three tissue compensators. Results The 3D-SRB was successfully designed and fabricated with a similar hardness to conventional bolus. During the process of validating conformability and radiotherapy planning,3D-SRB and 3D-PLA were superior to conventional bolus in terms of conformability to chest wall and planning dosimetric distribution.3D-SRB was advantageous in repeatability, conformability and comfortable experience compared with 3D-PLA. Regarding dosimetric parameters,3D-SRB yielded the highest repeatability with the virtual plan, followed by 3D-PLA and conventional bolus. Conclusion It is applicable to utilize 3D-SRB as the patient-specific compensators for the chest wall,which is of significance in clinical practice.

AIM: To investigate the correlation between the expression of serum lipocalin 2(LCN2), chemokine like receptor 1(CMKLR1), and C-C motif chemokine ligand 11(CCL11)and the severity of disease in patients with type 2 diabetes mellitus(T2DM)and dry eye(DE).METHODS:A prospective selection of 97 patients(194 eyes)diagnosed with T2DM and DE at our hospital from May 2022 to May 2024 was made as the DE group, which was further divided into mild(47 cases, 94 eyes), moderate(34 cases, 68 eyes), and severe(16 cases, 32 eyes)subgroups based on the severity of dry eye. Additionally, 97 patients(194 eyes)of T2DM without DE were selected as non-DE group, and 97 healthy volunteers(194 eyes)who underwent physical examination during the same period were chosen as control group. Serum levels of LCN2, CMKLR1, and CCL11 were measured in all participants. Spearman correlation analysis was used to assess the relationship between serum levels of LCN2, CMKLR1, and CCL11 and the severity of DE in T2DM patients; multivariate Logistic analysis was used to analyze the factors affecting the severity of T2DM patients with DE. The receiver operating characteristic(ROC)curve was drawn to analyze the diagnostic value of serum LCN2, CMKLR1 and CCL11 levels for moderate to severe dry eye in T2DM patients.RESULTS: Serum levels of LCN2, CMKLR1, and CCL11 increased progressively from the control group to the non-DE group and then to the DE group(all P<0.05). Within the DE group, these levels also increased progressively from the mild to moderate and then to the severe subgroups(all P<0.05). Spearman correlation analysis showed that serum levels of LCN2, CMKLR1, and CCL11 were positively correlated with the severity of disease(rs=0.604, 0.591, 0.559, respectively; all P<0.05). Stepwise forward multivariate Logistic analysis showed that Schirmer's test(SⅠt), tear break-up time(BUT), serum levels of LCN2, CMKLR1 and CCL11 were the factors affecting the severity of T2DM patients with DE; ROC curve analysis indicated that the combined diagnosis of serum LCN2, CMKLR1, and CCL11 for the progression of T2DM with DE to moderate-to-severe stages had an area under curve(AUC)value of 0.896, which was significantly higher than that of individual diagnoses of LCN2, CMKLR1, and CCL11(Z=2.925, 2.704, 3.483, respectively; P=0.003, 0.007, <0.001).CONCLUSION: Serum LCN2, CMKLR1 and CCL11 levels are increased in T2DM patients with DE, and are positively correlated with the severity of DE. The combination of the three has a high diagnostic value for moderate to severe DE.

AIM: To investigate the expression and clinical diagnostic value of toll-like receptor 4(TLR4)and nuclear factor-κB(NF-κB)in conjunctival epithelial cells and tears of patients with dry eye.METHODS: From January 2023 to June 2024, 104 dry eye patients(104 eyes, disease group)who visited our hospital and 100 healthy individuals(100 eyes, control group)who underwent physical examination were selected. The changes of TLR4 and NF-κB in conjunctival epithelial cells and tears were analyzed. Pearson analysis was applied to analyze the correlation between TLR4 and NF-κB expression in conjunctival epithelial cells and tears. Logistic analysis was applied to analyze the factors that affected dry eye. ROC was applied to analyze the diagnostic value of TLR4 and NF-κB expression in conjunctival epithelial cells and tears for dry eye.RESULTS: The differences in the use of eye drops, tear film break-up time(BUT), Schirmer's test(SⅠt), tear film thickness(TFT), and corneal fluorescein staining(CFS)scores between the disease group and the control group were statistically significant(all P<0.01). The expression levels of TLR4 and NF-κB in conjunctival epithelial cells and tears in the disease group were significantly higher than those in the control group(all P<0.01). There was a positive correlation between TLR4 and NF-κB in conjunctival epithelial cells and tears(r=0.392, 0.348, all P<0.05). Frequent use of eye drops, CFS score, TLR4, and NF-κB were risk factors for dry eye(OR=2.153, 3.183, 1.578, 2.452, all P<0.05), while BUT, SⅠt, and TFT were protective factors for dry eye(OR=0.654, 0.755, 0.276, all P<0.05). The sensitivity, specificity, and AUC of TLR4 combined with NF-κB in conjunctival epithelial cells in the diagnosis of dry eye were 86.54%, 81.00%, and 0.889, respectively. The combination of TLR4 and NF-κB had higher diagnostic value for dry eye than uncombined diagnosis(Zcombination-TLR4=3.506, P=0.001; Zcombination-NF-κB=3.165, P=0.002). The sensitivity, specificity, and AUC of TLR4 combined with NF-κB in tears for diagnosing dry eye were 82.69%, 70.00%, and 0.818, respectively. The combination of TLR4 and NF-κB in tears had higher diagnostic value for dry eye than uncombined diagnosis(Zcombination-TLR4=3.117, P=0.002; Zcombination-NF-κB=2.363, P=0.018).CONCLUSION: The expression levels of TLR4 and NF-κB in conjunctival epithelial cells and tears of patients with dry eye are elevated. TLR4 and NF-κB are related to the development of dry eye, and that elevated levels of both are associated with an increased risk of dry eye disease. The combination of TLR4 and NF-κB has a certain diagnostic significance for dry eye.