Effects of L-lactic acid and D,L-lactic acid on viability and osteogenic differentiation of mesenchymal stem cells

Abstract

Poly(lactic acid) (PLA) and other aliphatic polyesters containing the unit of lactic acid are very popular biodegradable materials. While the degradation products, lactic acids, have been worried to bring with negative influence on biocompatibility, the focused experimental studies are less reported. This study is aimed at an in vitro examination of cytotoxicity of both L-lactic acid and D,L-lactic acid. Mesenchymal stem cells (MSCs) derived from rat bone marrow are employed to test the cytotoxicity of the lactic acids. Considering that the addition of lactic acids not only introduces lactate groups but also alters medium pH and ion strength, these three candidate effects are examined in a decoupled way by setting different comparison groups. The results confirm that the change of medium pH is the predominant factor. It has also been found that D-lactate is more cytotoxic than L-lactate at high concentrations. Yet, either L-or D,L-lactic acids seem acceptable in most of medical applications, because the cytotoxicity is significant only when the concentrations are as high as 20 mmol/L for both of them.

Characterization of Olfactory Ensheathing Glial Cells Cultured on Polyurethane/Polylactide Electrospun Nonwovens

“…This monomer may be initially released at higher quantities during first days due to PLDL degradation; however, it should not influence cell viability. The lactic acid is one of the cell metabolism products during in vitro culture conditions, and its cytotoxicity has been observed only at high concentrations and correlated with a significant decrease in pH [59]. In this experiment, the significant changes in pH were excluded by the addition of HEPES buffer to the culture medium and proper medium change intervals, which was controlled by observations of phenol red-containing medium color.…”

“…Water contact angle was measured for determination of hydrophilic properties of the samples. The hydrophilicity of the fibrous scaffolds might play an essential role in the determination of their usability as cell culture substrates [59]. Table 1 summarized the contact angle values of polyurethane and PU/PLDL blends cast films and electrospun nonwovens.…”

Biomaterial‐Based Metabolic Regulation in Regenerative Engineering

“…Regulatory metabolite Citrate 100-2000 × 10 −6 m for promoted osteo-phenotype progression of hMSCs [80] 37.3 × 10 −3 m (EC50 for hMSCs [86] ); 10.9 × 10 −3 m (EC50 for MG63 [86] ); 10.5 × 10 −3 m (EC50 for 3T3 [86] ); Inorganic phosphate 5 × 10 −3 m for induced osteogenic differentiation of hMSCs [19] Not available Lactate 0.06-0.17 mg mL −1 for radical scavenging [92] 20 × 10 −3 m (critical toxic concentration for hMSCs [122] ) osteo-differentiation [35] to meet the increasing energy demand, the citrate-elevated cell energy status subsequently is favorable to fuel the high metabolic demand of hMSCs osteogenic differentiation, contributing to the accumulated Runx2 expression and an increase in production of bone-related extracellular matrix (Figure 5Aiii). In addition to regulatory metabolites, inorganic phosphate, serving as the direct substrate for ATP synthesis, was found in the degradation product of a mineralized matrix containing calcium phosphate prepared via biomineralization.…”

From Chinese Science Bulletin to Science Bulletin: celebrate the coming 50th birthday

“…Several well-known research laboratories have published their research work in Science Bulletin, which attracted tremendous attention from both general public and scientific community. Articles about stem cells in Science Bulletin cover the following aspects: nuclear reprogramming [63,64], mesenchymal stem cell differentiation [65], cell replacement therapy [66], induced pluripotent stem cell technology [67] and the generation of tetraploid complementation mice from embryonic stem cells [68,69]. A recent special topic entitled ''Stem cell, basis and application'' [70] covers diverse aspects and topics on stem cell studies including cell sources for iPSC generation, epigenetic roles in somatic reprogramming and embryonic development, and cell source for treating diseases, which updates the information of current advances in stem cell biology.…”