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Jiachen Yu,1,* Yingchun Zhang,1,* Rong Ran,2,* Zixiao Kong,3 Duoyi Zhao,1 Wei Zhao,1 Yingxin Yang,4 Lianbo Gao,5 Zhiyu Zhang1 1Department of Orthopedics, the Fourth Affiliated Hospital of China Medical University, China Medical University, Shen Yang, 110032, People’s Republic of China; 2Department of Anesthesia, the Fourth Affiliated Hospital of China Medical University, China Medical University, Shen Yang, 110032, People’s Republic of China; 3China Medical University, Shen Yang, 110032, People’s Republic of China; 4General Hospital of Northern Theater Command, China Medical University, Shen Yang, 110032, People’s Republic of China; 5Department of Neurology, the Fourth Affiliated Hospital of China Medical University, China Medical University, Shen Yang, 110032, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhiyu Zhang; Lianbo Gao, The Fourth Affiliated Hospital of China Medical University, No. 4 Chongshan Road, Huanggu District, Shenyang, Liaoning, People’s Republic of China, Email zyzhang@cmu.edu.cn; lbgao@cmu.edu.cnAbstract: The development of therapeutic drugs and methods has been greatly facilitated by the emergence of tumor models. However, due to their inherent complexity, establishing a model that can fully replicate the tumor tissue situation remains extremely challenging. With the development of tissue engineering, the advancement of bioprinting technology has facilitated the upgrading of tumor models. This article focuses on the latest advancements in bioprinting, specifically highlighting the construction of 3D tumor models, and underscores the integration of these two technologies. Furthermore, it discusses the challenges and future directions of related techniques, while also emphasizing the effective recreation of the tumor microenvironment through the emergence of 3D tumor models that resemble in vitro organs, thereby accelerating the development of new anticancer therapies.Keywords: bioprinting, bioink, organoids, tumor spheroids, tumor chips

Ziyan Kong,1,2,* Xuemei Liu,3,* Chenxi Li,1,* Siyun Cheng,1 Fei Xu,3 Bing Gu1,4 1Medical Technology School, Xuzhou Medical University, Xuzhou, Jiangsu Province, People’s Republic of China; 2Department of Laboratory Medicine, The First People’s Hospital of Lianyungang, Lianyungang, Jiangsu Province, People’s Republic of China; 3Department of Laboratory Medicine, Children’s Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, People’s Republic of China; 4Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Fei XuDepartment of Laboratory Medicine, Children’s Hospital of Nanjing Medical University, Nanjing 210009, People’s Republic of ChinaEmail 350826448@qq.comBing GuDepartment of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, People’s Republic of ChinaEmail gb20031129@163.comPurpose: The continuous emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a serious public health problem globally, especially for children, but data on CRKP infection in pediatric patients are limited. This study aimed to identify epidemiological and molecular patterns of CRKP among pediatric patients in Jiangsu province, China.Patients and Methods: CRKP were consecutively collected from the Children’s Hospital of Nanjing Medical University in China from July 2018 to May 2019. Then, CRKP strains were performed for further study: antimicrobial susceptibility testing, drug-resistance determinants screening and homology analysis.Results: We collected 94 CRKP from 94 children. Overall, blaKPC-2 (79.8%) was the predominant carbapenemase gene, followed by blaNDM-1(14.9%), blaIMP-4 (5.3%) and blaNDM-5(4.3%). Notably, two isolates coharbored blaKPC-2 and blaIMP-4, and two isolates coharbored blaKPC-2 and blaNDM-5. MLST analysis revealed that 14 distinct sequence types (STs) were identified, of which ST11 was the most common sequence type identified. Moreover, two novel STs, ST4854 and ST4855, were detected in this study. PFGE revealed that a predominant cluster consisting of KPC-2-producing CRKP ST11 clone isolates was identified and was distributed mainly in the pediatric intensive care unit (PICU) and cardiac intensive care unit (CCU). Moreover, this is the first report to identify the dissemination of ST716 CRKP coproducing KPC-2 and IMP-4 clones.Conclusion: Clonal dissemination of KPC-2-producing CRKP ST11 was observed in multiple departments. Moreover, two novel STs (ST4854 and ST4855) were identified, which indicates an increased diversity of CRKP strains. To our knowledge, this is the first report that identified the dissemination of Klebsiella pneumoniae coproducing KPC-2 and IMP-4 clones among children, which represents a significant health risk to pediatric patients. Active surveillance and effective control measures are urgently needed to prevent further transmission of these strains among children.Keywords: Klebsiella pneumoniae, carbapenemase, KPC-2, ST11, clonal dissemination, children

Ziyan Kong,1,* Rui Cai,1,* Chen Cheng,1 Chuanling Zhang,2 Haiquan Kang,3 Ping Ma,3 Bing Gu1,3 1Medical Technology School, Xuzhou Medical University, Xuzhou, Jiangsu Province, People’s Republic of China; 2Department of Laboratory Medicine, XuZhou Children’s Hospital, Xuzhou, Jiangsu Province, People’s Republic of China; 3Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Bing GuDepartment of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, People’s Republic of ChinaTel +8615862163560Email gb20031129@163.comPurpose: Carbapenem-resistant Klebsiella pneumoniae (CRKP) have emerged worldwide and also being a major threat to children and neonate. In this study, we describe a nosocomial outbreak of NDM-5-producing Klebsiella pneumoniae in neonatal unit of a teaching hospital in China from September 2015 to September 2016.Patients and methods: We collected 12 carbapenem-resistant K. pneumoniae outbreak strains from 12 newborns and characterized these isolates for their antimicrobial susceptibility, clone relationships, and multi-locus sequence types using vitek-2 compact system, pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Resistant genes were detected by using PCR and sequencing. Plasmid conjugation experiment was carried out to determine the transferability of carbapenem resistance. PCR-based replicon typing (PBRT), S1 nuclease-PFGE, and southern blotting were conducted for plasmid profiling.Results: All 12 K. pneumoniae isolates were resistant to carbapenems and carried blaNDM-5, blaTEM-1 and blaSHV-11. Furthermore, PFGE analysis showed that NDM-5-producing K. pneumoniae were clonally related and MLST assigned them to sequence type 337. Conjugative assays showed that plasmids harboring blaNDM-5 gene were self-transmissible. Plasmid analysis suggested that all blaNDM-5 gene located on a ∼45 kb IncX3 type plasmid.Conclusion: To the best of our knowledge, this is the first report of a clone outbreak of blaNDM-5-carrying K. pneumoniae isolates from neonates. There is an urgent need for effective infection control measures to prevent blaNDM-5 variants from becoming epidemic in the neonates in the future.Keywords: Klebsiella pneumoniae, carbapenemases, blaNDM-5, ST337, neonate, IncX3

C19H20N2O5Pb, triclinic, P1 (No. 2), a = 7.488(2) Å, b = 11.543(2) Å, c = 11.742(2) Å, α = 83.50(3)°, β = 82.54(3)°, γ = 81.94(3)°, V = 991.7 Å3, Z = 2, Rgt(F) = 0.046, wRref(F2) = 0.128, T = 293 K.

C14H26N2NiO12, monoclinic, C12/c1 (No. 15), a = 16.952(2) Å, b = 11.285(1) Å, c = 13.025(2) Å, β = 126.652(7)°, V = 1999.1 Å3, Z = 4, Rgt(F) = 0.041, wRref(F2) = 0.093, T = 293 K.

C12H16N2NiO8S, triclinic, P1̅ (No. 2), a = 7.968(1) Å, b = 8.571(1) Å, c = 11.555(1) Å, α = 91.95(1)°, β = 92.08(1)°, γ = 104.31(1)°, V = 763.4 Å3, Z = 2, Rgt(F) = 0.043, wRref(F2) = 0.118, T = 293 K.