Page 74 - ARNM-3-3

Advances in Radiotherapy
& Nuclear Medicine CS@LGG for acute radiation-induced bowel injury alleviation

radiotherapy (25 Gy/5 f) as a potential therapy for locally In the present study, we aimed to optimize and improve
advanced rectal cancer. However, this approach unavoidably existing therapies by synthesizing a new therapeutic
leads to a higher and more severe incidence of radiation probiotic biomaterial, CS@LGG, and further explore its
injury, especially in patients undergoing comprehensive therapeutic effects, biosafety, and underlying mechanism
treatments, including surgery, chemotherapy, and in alleviating acute bowel injury after irradiation (IR).
immunotherapy. Generally, this side effect not only affects
the progress of tumor treatment and the overall prognosis, 2. Materials and methods
but also greatly reduces patients’ quality of life (QoL). 2.1. Materials and strains
2
Moreover, there is still a lack of individualized treatments
for these patients and limited clinical research evidence to CS was obtained from MackLin Co., Ltd. (Shanghai,
support their efficacy. Therefore, relieving acute radiation- China). Glacial acetic acid was purchased from Fdbio
induced intestinal injury remains an urgent and important Science Co., Ltd. (Guangzhou, China). Trypsin-
scientific problem in radiotherapy. 6 ethylenediaminetetraacetic acid (EDTA), penicillin, and
streptomycin were obtained from New Cell and Molecular
According to recent research evidence, radiation-
induced bowel damage is resulted from the high sensitivity Biotech Co., Ltd (Suzhou, China). Bovine serum albumin
of intestinal epithelial cells to radiation, release of (10%) was purchased from ACMEC Biochemical Co., Ltd
7-9
reactive oxygen species, and production of inflammatory (Shanghai, China). Fetal bovine serum (FBS) and Dulbecco’s
cytokines in vivo, all of which can damage the intestinal Modified Eagle Medium (DMEM) were obtained from
10
barrier and disrupt the balance of intestinal flora and Gibco (CA, USA). EDTA, 0.25%, eosin staining (BL727A),
microecology. Thus, the key principles of addressing neutral balsam (BL704A), and 1×phosphate-buffered saline
11
the bowel damage lie in inflammation relief and flora (PBS) were purchased from Biosharp (Shanghai, China).
regulation. Due to the broad adoption of probiotics- Paraformaldehyde (PFA, 4%) tissue fixative, crystal violet
12
related therapies in clinical settings, their specific effects (DZ0055), and hematoxylin (Lillie-Mayer type, BL727A)
on radiation-induced bowel injury have become a research were obtained from Leagen Biotechnology Co., Ltd
hotspot. Interestingly, some studies have proven that (Beijing, China). 3, 3-diaminobenzidine (DAB) substrate
proper use of probiotics can effectively alleviate radiation- (DAB-1031) was purchased from MXB Biotechnology
induced bowel injury. According to the expert consensus Co., Ltd (Fujian, China). Culture dishes (100 mm) and
in the 2023 edition on radioactive intestinal injury, fecal flask (T25) were obtained from Wuxi NEST Biotechnology
microbiota transplantation (FMT), as an emerging Co., Ltd (Jiangsu, China). The alkaline comet assay kit was
13
treatment to restore intestinal flora balance, has also been purchased from KeyGEN Biotechnology Co., Ltd (Jiangsu,
preliminarily applied in clinical practice. 12,14 Unfortunately, China). Enzyme-linked immunosorbent assay (ELISA)
due to insufficient evidence regarding its safety and efficacy, kits of IL-6, tumor necrosis factor alpha (TNFα), and IL-1β
it is still not widely accepted as a preferred therapy. In this (ELK, ELK1156, ELK1157, ELK1387) were purchased
regard, supplementation with probiotics through exogenous from ELK Biotechnology Co., Ltd (Wuhan, China). Ki67
properties seems to be a decent recommendation. 13,15,16 and γH2A.X antibodies were obtained from Cell Signaling
Indeed, present research has indicated that commonly Technology Co., Ltd (Boston, USA). Occludin (OCCLDN)
used probiotics, such as Lactobacillus, Bifidobacterium, and claudin-3 (CLDN3) antibodies were purchased from
Enterococcus, and lactic acid bacteria, can help patients Invitrogen Trading Shanghai Co., Ltd (Shanghai, China).
recover from diarrhea, abdominal pain, and distension, Fluorescein isothiocyanate (FITC)-conjugated phalloidin,
improving their QoL after radiotherapy. Among 4’,6-diamidino-2-phenylindole, and FITC-dextran were
14
these probiotics, Lactobacillus rhamnosus GG (LGG) is obtained from Sigma-Aldrich (St. Louis, USA). L-ascorbic
particularly prominent due to its ease of cultivation, better acid (vitamin C, ST1434-100g), L-glutathione reduced
colonization, and wide applications. 17-19 (GSH, ST2474-25g), and cell counting kit-8 (CCK-8)
However, due to its poor tolerance and viability in vitro, kit were purchased from Beyotime (Shanghai, China).
and the potential to cause bacteremia in vivo, the use of De Man, Rogosa, and Sharpe (MRS) broth was obtained
macromolecular polymers is strongly recommended to from Solarbio Life Sciences Co., Ltd (Beijing, China).
overcome these limitations. Among the available materials, LGG; ATCC 53103 was purchased from China General
pre-biotic chitosan (CS) stands as a preferable choice. 20-22 Microbiological Culture Collection Center. C57BL/6
It can be used as an energy-supplying substance in vitro, mice were obtained from Zhiyuan Biotechnology Co.,
enhancing the stability and efficacy of probiotics. In Ltd (Guangzhou, China). MC38 tumor cells and IEC-6
22
addition, water absorption capacity” can be removed for epithelial cells were purchased from NEWGAINBIO Co.,
its redundancy. 23 Ltd (Jiangsu, China).

Volume 3 Issue 3 (2025) 66 doi: 10.36922/ARNM025230026