Objective: To identify an optimal back-flush solution for leukocyte-depleted filters that maximizes peripheral blood mononuclear cell (PBMC) recovery with high viability, long-term storage stability, and sterility of the harvested residues, thereby providing a clinically translatable strategy. Methods: Three sterile bag-packaged solutions—Saline, Solvent, and Hanks' balanced salt solution (HBSS)—were used to back-flush randomly assigned leukocyte-depleted filters. Nucleated cell recovery rate and viability of the harvested residues were compared. The optimal solution identified was applied to an expanded sample set. PBMC viability and yield were evaluated after 1h vs 48h storage of the residues. PBMCs isolated from the residues were cryopreserved in liquid nitrogen for 1 month, followed by post-thaw comparisons of viability and T-cell expansion capacity. Results: The Solvent group achieved the highest and most consistent nucleated cell recovery rate. Post-flush recovery rate from filters after 400 mL whole blood processing was (21.3±1.6)% for the Solvent group, significantly higher than Saline group (19.2±6.3)% and HBSS group (11.2±5.0)%, with residues from all groups maintaining viability >90%. No biologically significant difference in residue viability was observed between 48h vs 1h storage groups (93.3±2.3)% vs (95.7±1.8)%). PBMC recovery rates from residues showed no statistical difference between 48h vs 1h storage groups [(48.2%±9.5%)vs (40.41%±8.35%), P>0.05], with (17.7±2.6)×10 cells. After 1-month cryopreservation and 10-day expansion, PBMCs isolated from 48-hour-stored residues retained (91.2±3.2)% viability and achieved a (61.9±15.9)-fold expansion. Conclusion: The bag-packaged Solvent, as a back-flush solution, enables sterile acquisition of leukocyte-depleted filter residues through closed-system tubing connections. These residues maintained PBMC viability and recovery rates after 48h storage at 2℃-8℃, with post-cryopreservation (1-month liquid nitrogen) viability and expansion capacity remaining stable. This protocol complies with blood bank regulatory criteria, addresses the concerns about the infectious window period in cell therapy raw materials, and provides a clinically translatable strategy for PBMC-based applications.

OBJECTIVES: To characterize the biological properties of double-negative T (DNT) cells isolated from leukoreduction filter residues. METHODS: Leukoreduction filters containing residues from 400 mL whole blood units (n=6) were collected from a blood center. Filters were back-flushed with normal saline, and the eluate was concentrated to obtain leukoreduction filter residues. Leukocytes in the residues were counted by dual-fluorescence staining. DNT cells were then isolated from the residues using antibody-mediated adsorption and density gradient centrifugation. Both cryopreserved and fresh unstimulated DNT cells derived from the residues were subjected to in vitro culture. Following culture, cells were assessed for expansion fold, viability, immunophenotype, differentiation status, and cytotoxicity against target cells using dual-fluorescence staining and flow cytometry, with comparisons made to DNT cells derived from whole blood. RESULTS: The leukocyte recovery rate achieved through reverse flushing of the leukocyte reduction filter was (41.9±14.7)%. Compared to whole blood, the DNT cell starting material obtained from filter residues showed no significant difference in total T-cell content (P>0.05). However, the viability and purity of the resulting DNT cell starting materials were significantly lower (both P<0.05). After 17 days of culture, DNT cells from filter residues and whole blood showed no significant differences in expansion fold, immunophenotype, differentiation status, or cytotoxicity toward target cells (all P>0.05). However, the viability of DNT cells from residues was significantly lower than that of whole blood-derived DNT cells [(86.0±4.2)% vs. (92.2±1.2)%, P<0.05]. After thawing (post 3 or 15 days of cryopreservation) and 17 days of culture, DNT cell starting materials from residues showed comparable immunophenotype, expansion fold, and differentiation status to their non-cryopreserved counterparts from the same source (all P>0.05). However, the viability of DNT cells cryopreserved for 3 days [92.4% (91.8%, 92.8%)] and the cytotoxicity against target cells of those cryopreserved for 15 days [91.3% (89.4%, 95.1%)] were significantly higher than those of non-cryopreserved DNT cells [87.8% (82.0%, 89.0%) and 70.9% (67.3%, 80.2%), respectively] (P<0.05). CONCLUSIONS DNT cells derived from leukoreduction filter residues exhibited highly comparable characteristics to those from whole blood in terms of expansion, purity, differentiation, and biological potency. Furthermore, their biological activity post-cryopreservation and revival remained largely similar to non-cryopreserved cells. These findings suggest that leukoreduction filter residues represent a promising alternative source of starting material for manufacturing off-the-shelf, allogeneic DNT cell therapeutics.

Objective To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue,so as to provide reference for future major events.Methods A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted.Ten emer-gency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones.The blood temperature during the drone flight were monitored,the cold chain control during drone flight was evaluated,and the application of drone flight was reviewed.Results During the Hangzhou Asian Games,a total of 14 drones were used for blood delivery.The delivery time(min)by drone from the blood station to one of the designated hospitals was 11.83±0.09,and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land de-livery(P＜0.05),meanwhile was 17.50±0.08,24.50±3.27 and 26.57±3.23 respectively to the other hospital(P＜0.05).Compared with land emergency blood delivery and routine blood delivery,blood delivery time by drone was much shorter,demonstrating better timeliness and stability.The temperature monitoring during the drone delivering showed that the suspen-ded red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃,with a temperature difference of 0.5-0.9℃ and 0.2-1.0℃ between takeoff and landing respectively,demonstrating that the blood cold chain was under control,and the delivery ran safely and smoothly.Conclusion During major events,the use of drones for emergency blood delivery ensures the quality of the blood,with good timeliness,feasibility and operability,and is worthy of promotion and applica-tion.

Objective To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue,so as to provide reference for future major events.Methods A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted.Ten emer-gency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones.The blood temperature during the drone flight were monitored,the cold chain control during drone flight was evaluated,and the application of drone flight was reviewed.Results During the Hangzhou Asian Games,a total of 14 drones were used for blood delivery.The delivery time(min)by drone from the blood station to one of the designated hospitals was 11.83±0.09,and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land de-livery(P＜0.05),meanwhile was 17.50±0.08,24.50±3.27 and 26.57±3.23 respectively to the other hospital(P＜0.05).Compared with land emergency blood delivery and routine blood delivery,blood delivery time by drone was much shorter,demonstrating better timeliness and stability.The temperature monitoring during the drone delivering showed that the suspen-ded red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃,with a temperature difference of 0.5-0.9℃ and 0.2-1.0℃ between takeoff and landing respectively,demonstrating that the blood cold chain was under control,and the delivery ran safely and smoothly.Conclusion During major events,the use of drones for emergency blood delivery ensures the quality of the blood,with good timeliness,feasibility and operability,and is worthy of promotion and applica-tion.

【Objective】 To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue, so as to provide reference for future major events. 【Methods】 A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted. Ten emergency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones. The blood temperature during the drone flight were monitored, the cold chain control during drone flight was evaluated, and the application of drone flight was reviewed. 【Results】 During the Hangzhou Asian Games, a total of 14 drones were used for blood delivery. The delivery time(min) by drone from the blood station to one of the designated hospitals was 11.83±0.09, and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land delivery (P<0.05), meanwhile was 17.50±0.08, 24.50±3.27 and 26.57±3.23 respectively to the other hospital(P<0.05). Compared with land emergency blood delivery and routine blood delivery, blood delivery time by drone was much shorter, demonstrating better timeliness and stability. The temperature monitoring during the drone delivering showed that the suspended red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃, with a temperature difference of 0.5-0.9 ℃ and 0.2-1.0℃ between takeoff and landing respectively, demonstrating that the blood cold chain was under control, and the delivery ran safely and smoothly. 【Conclusion】 During major events, the use of drones for emergency blood delivery ensures the quality of the blood, with good timeliness, feasibility and operability, and is worthy of promotion and application.

Objective To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue,so as to provide reference for future major events.Methods A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted.Ten emer-gency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones.The blood temperature during the drone flight were monitored,the cold chain control during drone flight was evaluated,and the application of drone flight was reviewed.Results During the Hangzhou Asian Games,a total of 14 drones were used for blood delivery.The delivery time(min)by drone from the blood station to one of the designated hospitals was 11.83±0.09,and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land de-livery(P＜0.05),meanwhile was 17.50±0.08,24.50±3.27 and 26.57±3.23 respectively to the other hospital(P＜0.05).Compared with land emergency blood delivery and routine blood delivery,blood delivery time by drone was much shorter,demonstrating better timeliness and stability.The temperature monitoring during the drone delivering showed that the suspen-ded red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃,with a temperature difference of 0.5-0.9℃ and 0.2-1.0℃ between takeoff and landing respectively,demonstrating that the blood cold chain was under control,and the delivery ran safely and smoothly.Conclusion During major events,the use of drones for emergency blood delivery ensures the quality of the blood,with good timeliness,feasibility and operability,and is worthy of promotion and applica-tion.

Objective To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue,so as to provide reference for future major events.Methods A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted.Ten emer-gency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones.The blood temperature during the drone flight were monitored,the cold chain control during drone flight was evaluated,and the application of drone flight was reviewed.Results During the Hangzhou Asian Games,a total of 14 drones were used for blood delivery.The delivery time(min)by drone from the blood station to one of the designated hospitals was 11.83±0.09,and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land de-livery(P＜0.05),meanwhile was 17.50±0.08,24.50±3.27 and 26.57±3.23 respectively to the other hospital(P＜0.05).Compared with land emergency blood delivery and routine blood delivery,blood delivery time by drone was much shorter,demonstrating better timeliness and stability.The temperature monitoring during the drone delivering showed that the suspen-ded red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃,with a temperature difference of 0.5-0.9℃ and 0.2-1.0℃ between takeoff and landing respectively,demonstrating that the blood cold chain was under control,and the delivery ran safely and smoothly.Conclusion During major events,the use of drones for emergency blood delivery ensures the quality of the blood,with good timeliness,feasibility and operability,and is worthy of promotion and applica-tion.

Objective To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue,so as to provide reference for future major events.Methods A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted.Ten emer-gency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones.The blood temperature during the drone flight were monitored,the cold chain control during drone flight was evaluated,and the application of drone flight was reviewed.Results During the Hangzhou Asian Games,a total of 14 drones were used for blood delivery.The delivery time(min)by drone from the blood station to one of the designated hospitals was 11.83±0.09,and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land de-livery(P＜0.05),meanwhile was 17.50±0.08,24.50±3.27 and 26.57±3.23 respectively to the other hospital(P＜0.05).Compared with land emergency blood delivery and routine blood delivery,blood delivery time by drone was much shorter,demonstrating better timeliness and stability.The temperature monitoring during the drone delivering showed that the suspen-ded red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃,with a temperature difference of 0.5-0.9℃ and 0.2-1.0℃ between takeoff and landing respectively,demonstrating that the blood cold chain was under control,and the delivery ran safely and smoothly.Conclusion During major events,the use of drones for emergency blood delivery ensures the quality of the blood,with good timeliness,feasibility and operability,and is worthy of promotion and applica-tion.

Objective To explore the application of drones in blood emergency support during the 19th Asian Games Hangzhou in Shaoxing venue,so as to provide reference for future major events.Methods A retrospective analysis of drone delivery of emergency blood to two designated rescue hospitals in Shaoxing for the Asian Games was conducted.Ten emer-gency and 30 routine land blood delivery records from two designated hospitals in 2023 were randomly selected to compare with the blood delivery using drones.The blood temperature during the drone flight were monitored,the cold chain control during drone flight was evaluated,and the application of drone flight was reviewed.Results During the Hangzhou Asian Games,a total of 14 drones were used for blood delivery.The delivery time(min)by drone from the blood station to one of the designated hospitals was 11.83±0.09,and 20.80±3.29 by emergency land delivery and 23.23±3.54 by routine land de-livery(P＜0.05),meanwhile was 17.50±0.08,24.50±3.27 and 26.57±3.23 respectively to the other hospital(P＜0.05).Compared with land emergency blood delivery and routine blood delivery,blood delivery time by drone was much shorter,demonstrating better timeliness and stability.The temperature monitoring during the drone delivering showed that the suspen-ded red blood cells and platelets were in a range of 3.8-6.8℃ and 21.8-22.8℃,with a temperature difference of 0.5-0.9℃ and 0.2-1.0℃ between takeoff and landing respectively,demonstrating that the blood cold chain was under control,and the delivery ran safely and smoothly.Conclusion During major events,the use of drones for emergency blood delivery ensures the quality of the blood,with good timeliness,feasibility and operability,and is worthy of promotion and applica-tion.

【Objective】 To evaluate the screening efficacy and practical value of the portable microfluidic biochemical analyzer in the detection of blood donors before blood donation. 【Methods】 Blood donor samples, clinical blood samples and constant quality control products were collected. Referring to the documents of ISO15189 and National Health Industry Standard, the precision and accuracy of hemoglobin (Hb) and alanine aminotransferase (ALT) were verified and compared with other detection systems. 【Results】 The MS200 biochemistry instrument has an intra-batch precision of 1.40% to 1.46%, inter-batch precision of 1.91% to 1.94%, and correctness bias of -0.9% to -1.3% for Hb test, and an intra-batch precision of 3.77% to 4.86%, inter-batch precision of 4.92% to 6.02%, and correctness bias of -3.0% to -4.8% for ALT test, which were within the range of quality requirements of industry standard. Comparison of Hb test results between MS200 biochemistry and Hb201 analyser on 1 189 peripheral blood samples from donors showed no statistically significant difference (P>0.05). 65 samples showed positive correlation between MS200 biochemistry and XS-900i automated hematology analyzer on Hb test results (R²=0.986, P=0.000). Correlation analysis of all the results of ALT detection by MS200 biochemical analyzer and AU480 biochemical analyzer in 1 065 samples showed a positive correlation (R²=0.965, P=0.000). The elevated ALT samples did not affect the Hb test results, and the samples with abnormal Hb value did not affect the ALT test results, with no interference between the two items in the detection. 【Conclusion】 The MS200 biochemical analyzer based on microfluidic technology has reliable methodological performance and can meet the need of pre-donation testing.