Polymer‐Controlled, Bio‐Inspired Calcium Phosphate Mineralization from Aqueous Solution

Abstract

Nowadays, the majority of the commercially available calcium phosphate materials is fabricated by 'classical' materials science approaches, i.e., from rather poorly defined slurries or from organic solvents, often at high temperatures and pressures. Bioinspired precipitation of inorganics with (polymeric) additives from aqueous solution, on the other hand, enables the synthesis of intriguing inorganic or organic/inorganic materials that are often much more closely related to biological structures. This article discusses approaches for the fabrication of bio-inspired calcium phosphate hybrid materials by precipitation from aqueous solution. The article focuses on polymers and related self-assembling structures for the design of CaP/organic hybrids and pure CaP with crystal structures and morphologies regulated by the respective additive.

Water-Soluble Cellulose Derivatives Are Sustainable Additives for Biomimetic Calcium Phosphate Mineralization

“…Possibly, this is correlated to the inhomogeneous distribution of nitrate ions and/or ammonium nitrate. Such an observation is also consistent with previous examples of calcium phosphate/cellulose hybrid materials [30] and with many bioinspired calcium phosphate precipitates in general [5,6].…”

“…Consistent with previous studies [5], higher polymer concentrations and lower precursor concentrations lead to a material that is closer to a "real" hybrid material, while inverse conditions lead to samples that are more closely related to the control samples. Moreover, the crystal phase selection (HAP vs. DCPD in the current study) is not determined by the chemistry of the polymer additive, but by the precursor concentrations and the pH changes occurring during the mineralization process ( Figure 7); this observation is also consistent with literature [5,6].…”

“…As a result, the development of biomineralization-inspired (bio)materials based on renewable resources and via sustainable processes is of ever growing importance. Interestingly, however, although a large number of publications on bioinspired mineralization of calcium phosphate is available (see refs [5,6] for extensive reviews of the field), the number of studies on mineralization additives based on renewable raw materials is still rather limited. Carbohydrates are particularly interesting for hybrid (bio)materials development because they are available in large amounts and numerous protocols for their chemical modification exist [7].…”

Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization

“…This is oen achieved via polymer additives that aid the calcium phosphate mineralization process. While there is a large body of work on polymer-controlled biomimetic calcium phosphate mineralization in general [27][28][29] only a small fraction of the work focuses on dental applications.…”

“…6 (A) Ca/P ratios obtained from EDX data of precipitates and (B) XRD patterns of precipitates. 86 The dashed lines in (A) represent the Ca/P ratios of the different calcium phosphate phases 28 OCP is octacalcium phosphate, ACP is amorphous calcium phosphate, HAP is hydroxyapatite, and DCPA is dicalcium phosphate anhydrate (monetite). dissolution efficiency vs. numbers of functional monomers instead of polymer concentration and hence allows for the determination of relative dissolution effectiveness.…”