Amorphous polyphosphate nanoparticles: application of the morphogenetically active inorganic polymer for personalized tissue regeneration

Abstract

Inorganic polyphosphate (polyP) is one of the oldest chemical energy-providing molecules in biological systems. This polymer, containing a much longer sequence of high-energy phosphate units than the universal energy donor adenosine triphosphate, has attracted increasing attention for potential biomedical applications because of its diverse metabolic and regulatory functions and its ability to form biologically active nano/microparticles. The morphogenetic properties (stimulation of cell growth and differentiation via gene induction) of polyP nano/microparticles, prepared in an amorphous form, and their combination with hydrogel-forming polymers enabled the development of 3D-printable and hardenable hybrid materials for personalized tissue regeneration/repair. Depending on the counterion of the polyanionic polyP, both the physical (hardness, stiffness) and the biological properties (induction of cytokines, enzymes or structural proteins) of the 3D-printed scaffolds can be modulated. In this way, individualized scaffolds/implants, even loaded with cells, which can be adapted to specific tissue defects (e.g. of bone and cartilage), can be fabricated. This topical review summarizes the physical–chemical properties and biological effects of polyP, formulated as smart amorphous nano/microparticles, and its application to produce personalized 3D-scaffolds/implants that open new possibilities in regenerative medicine.

Engaging a Battle on Two Fronts: Dual Role of Polyphosphates as Potent Inhibitors of Struvite Nucleation and Crystal Growth

“…Moreover, it is interesting to point out that previous studies have demonstrated the presence of particles in solutions comprised of PolyPs and cationic species (e.g., Mg 2+ ions). Similar types of particulates containing PolyPs and inorganic divalent cations have also been observed in nature, such as granules in mitochondria, while synthetic analogues can be prepared in alkaline solutions with excess cations − for use in applications of bone regeneration and cartilage repair, among others.…”

“…Mg 2+ ions). Similar types of particulates containing PolyPs and inorganic divalent cations have also been observed in nature, such as granules in mitochondria, while synthetic analogues can be prepared in alkaline solutions with excess cations [61][62][63][64] for use in applications of bone regeneration 65 and cartilage repair 64 , among others.…”

Novel, degradable, and cytoactive bone cements based on magnesium polyphosphate and calcium citrate

“…3D), the peak attributed to the symmetrical stretching vibration of –COO −36 at 1432 cm −1 was weakened, and no peak was detected for the N–H bond. The wide peak at ∼1123 cm −1 was attributed to the overlap of asymmetric stretching vibration peaks of (PO 3 ) 2–22,33 and the C–O bond. 39 The P–O–P bond belonging to polyphosphate was clearly observed.…”

“…At the same time, polyphosphate, being an anionic polymer, can regulate the biological properties of materials by chelating different divalent cations. 20 For example, magnesium, which is widely used, presents good biocompatibility and biodegradability. 21 Schroder et al 20 claimed that magnesium polyphosphate (MPP) can promote the differentiation of bone marrow mesenchymal stem cells in cartilage cell lines and accelerate cartilage regeneration.…”

“…20 For example, magnesium, which is widely used, presents good biocompatibility and biodegradability. 21 Schroder et al 20 claimed that magnesium polyphosphate (MPP) can promote the differentiation of bone marrow mesenchymal stem cells in cartilage cell lines and accelerate cartilage regeneration. Mu ¨ller et al 22 prepared a viscous paste-like biological matrix using MPP and hyaluronic acid.…”