Synthesis and characterization of hypoxia-mimicking bioactive glasses for skeletal regeneration
Synthesis and characterization of hypoxia-mimicking bioactive glasses for skeletal regeneration
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DOI：
10.1039/c0jm01111h
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发表时间：
2010-01-01
影响因子：
--
通讯作者：
Stevens, M. M.
中科院分区：
文献类型：
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作者：
Azevedo, M. M.;Jell, G.;Stevens, M. M.
细胞对低氧(低氧压)的反应对骨骼组织的发育和再生至关重要。许多过程，包括祖细胞募集、分化和血管生成，都是通过低氧途径被激活的。因此，设计新的基于材料的策略来激活缺氧途径是骨科组织工程的重要研究方向。可吸收生物活性玻璃(BGS)通过控制钴离子(生理相关浓度)的释放来激活缺氧途径，同时控制BG磷灰石的形成能力。随着钴含量的增加，合成了两个系列的钠钙磷硅酸盐玻璃。考虑到钴在第一系列中参与网络，并在第二系列中充当网络修饰剂，计算组成以维持恒定的网络连接性(2.13)。在其中一种含Co2+的玻璃中加入镁、锌离子以抑制HCA的形成。在软组织如软骨中使用BG时，Hca的形成是不可取的。钴同时存在于BG的硅酸盐和磷酸盐相中。此外，有证据表明，它在硅酸盐相中起着双重作用，既进入了网络，又作为网络修饰氧化物破坏了网络。与这一双重作用一致的是，BG中钴的存在显示出减少离子释放。钴的加入以及镁、锌离子的掺入延缓了Hca的形成。重要的是，钴的释放被发现与BGS中的钴含量成正比，从而能够以治疗活性剂量受控地输送钴。
The cellular response to hypoxia (low oxygen pressure) is vital for skeletal tissue development and regeneration. Numerous processes, including progenitor cell recruitment, differentiation and angiogenesis, are activated via the hypoxia pathway. Novel materials-based strategies designed to activate the hypoxia pathway are therefore of great interest for orthopaedic tissue engineering. Resorbable bioactive glasses (BGs) were developed to activate the hypoxia pathway by the controlled release of cobalt ions (at physiological relevant concentrations) whilst controlling BG apatite-forming ability. Two series of soda-lime-phosphosilicate glasses were synthesised with increasing concentrations of cobalt. Compositions were calculated to maintain constant network connectivity (2.13) by considering that cobalt is taking part in the network in the first series, and is acting as a network modifier in the second series. Mg2+ and Zn2+ were added to one of the Co2+-containing glasses to inhibit HCA formation. The presence of HCA formation is undesirable for the use of BG in soft tissues e. g. cartilage. Cobalt was present in both the silicate and phosphate phases of the BG. In addition, evidence was found that it plays a dual role in the silicate phase, entering the network as well as disrupting it as a network modifying oxide. Consistent with this dual role, the presence of cobalt in the BG was shown to decrease ion release. HCA formation was delayed with cobalt addition as well as incorporation of Mg2+ and Zn2+ into the BGs. Importantly, cobalt release was found to be proportional to cobalt content of the BGs enabling the controlled delivery of cobalt in therapeutically active doses.