RRC ID 69880
Author Nishino K, Tamai K, Orita K, Hashimoto Y, Nakamura H.
Title Heated Tobacco Products Impair Cell Viability, Osteoblastic Differentiation, and Bone Fracture-Healing.
Journal J Bone Joint Surg Am
Abstract BACKGROUND:The negative impact of cigarette smoking on bone union has been well documented. However, the impact of heated tobacco product (HTP) use on bone fracture-healing remains unclear. The present study investigated the effect of HTPs on preosteoblast viability, osteoblastic differentiation, and fracture-healing and compared the effects with those of conventional combustible cigarettes.
METHODS:Cigarette smoke extracts (CSEs) were generated from combustible cigarettes (cCSE) and HTPs (hCSE). CSE concentrations were standardized by assessing optical density. Preosteoblast (MC3T3-E1) cells were incubated with normal medium, cCSE, or hCSE. The cell viability was assessed via MTT assay. After osteoblastic differentiation of CSE-exposed cells, alkaline phosphatase (ALP) activity was assessed. To assess the in vivo effects of CSEs, a femoral midshaft osteotomy was performed in a rat model; thereafter, saline solution, cCSE, or hCSE was injected intraperitoneally, and bone union was assessed on the basis of micro-computed tomography (μCT) and biomechanical analysis 4 weeks later.
RESULTS:MC3T3-E1 cell viability was reduced in a time and concentration-dependent manner when treated with either cCSE or hCSE. ALP activity after osteoblastic differentiation of cCSE-treated cells was significantly lower than that of both untreated and hCSE-treated cells (mean and standard deviation, 452.4 ± 48.8 [untreated], 326.2 ± 26.2 [cCSE-treated], and 389.9 ± 26.6 [hCSE-treated] mol/L/min; p = 0.002). Moreover, the levels of osteoblastic differentiation in untreated and hCSE-treated cells differed significantly (p < 0.05). In vivo assessment of the femoral midshaft cortical region revealed that both cCSE and hCSE administration significantly decreased bone mineral content 4 weeks after surgery compared with levels observed in untreated animals (107.0 ± 11.9 [untreated], 94.5 ± 13.0 [cCSE-treated], and 89.0 ± 10.1 mg/cm3 [hCSE-treated]; p = 0.049). Additionally, cCSE and hCSE-exposed femora had significantly lower bone volumes than unexposed femora. Biomechanical analyses showed that both cCSE and hCSE administration significantly decreased femoral maximum load and elastic modulus (p = 0.015 and 0.019).
CONCLUSIONS:HTP use impairs cell viability, osteoblastic differentiation, and bone fracture-healing at levels comparable with those associated with combustible cigarette use.
CLINICAL RELEVANCE:HTP use negatively affects bone fracture-healing to a degree similar to that of combustible cigarettes. Orthopaedic surgeons should recommend HTP smoking cessation to improve bone union.
Volume 103(21)
Pages 2024-2031
Published 2021-11-3
DOI 10.2106/JBJS.20.02227
PII 00004623-990000000-00306
PMID 34730563
MeSH Animals Cell Differentiation / drug effects Cell Line Cell Survival / drug effects Disease Models, Animal Femur / injuries Fracture Healing / drug effects* Heating / adverse effects* Humans Male Mice Osteoblasts / drug effects Osteoblasts / physiology Rats Tobacco Products / adverse effects* Tobacco Use / adverse effects* X-Ray Microtomography
Human and Animal Cells MC3T3-E1(RCB1126)