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11 pages, 6396 KiB

Open AccessArticle

The Influence of Chitosan on Water Absorption and Solubility of Calcium Phosphate Cement

by Ioana Lacan, Mărioara Moldovan and Ioan Ardelean

Coatings 2023, 13(9), 1641; https://doi.org/10.3390/coatings13091641 - 18 Sep 2023

Cited by 4 | Viewed by 1739

Calcium phosphate cements are widely used biomaterials for bone regeneration due to their biological properties, such as biocompatibility, biodegradability, and bioactivity. The presence of chitosan in cement composition influences the resorption rate of the material and its mechanical properties. In the present work, the water absorption and solubility of a tricalcium phosphate bone cement, prepared with and without chitosan addition, was comparatively evaluated. The absorption and solubility properties were monitored for 21 days by immersing the samples in water at room temperature and then weighing them. A morphological analysis of the samples was carried out via scanning electron microscopy (SEM). The absorption dynamics and pore evolution were investigated with low-field nuclear magnetic resonance (NMR) relaxometry. It was demonstrated that the presence of chitosan accelerates the hardening dynamics, reduces water absorption, and influences the solubility and degradation behavior of the cement. It was also observed that, independent of the presence of chitosan, the polymerization process is not completed even after one hour, which influences the solubility process. It was also shown that the presence of chitosan reduces the amount of microcracks and improves the functional properties of the hardened cement. Full article

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8 pages, 2326 KiB

Open AccessArticle

Chitosan Effect on Hardening Dynamics of Calcium Phosphate Cement: Low-Field NMR Relaxometry Investigations

by Ioana Lacan, Mărioara Moldovan, Codruța Sarosi and Ioan Ardelean

Polymers 2022, 14(15), 3042; https://doi.org/10.3390/polym14153042 - 27 Jul 2022

Cited by 4 | Viewed by 1756

Abstract

Calcium phosphate cements are used in dentistry and orthopedics to repair and reconstruct bone defects. The properties of these bone cements can be improved by introducing additives into their composition. One favorable additive is chitosan, which can be beneficial but can also cause considerable damage if it has a high load, thus, limiting its clinical applicability and performance. That is why understanding chitosan’s role in cement composition is an important issue when developing new materials. The present work uses low-field nuclear magnetic resonance (NMR) relaxometry to investigate the effect introduced by the addition of chitosan on the hardening process of calcium phosphate cement. Two samples, prepared with and without chitosan, were comparatively investigated during the first six minutes of hardening. The liquid evolution inside these samples was monitored using transverse relaxation time distributions. It demonstrated an acceleration effect on the hardening dynamics introduced by the presence of chitosan. Furthermore, it was shown that even after one hour of hardening, there were still unreacted monomers inside the bone cement and their amount was reduced in the presence of chitosan. Full article

(This article belongs to the Section Polymer Analysis and Characterization)

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10 pages, 1986 KiB

Open AccessArticle

Magnetic Calcium Phosphate Cement for Hyperthermia Treatment of Bone Tumors

by Ethel Ibinabo Ruskin, Paritosh Perry Coomar, Prabaha Sikder and Sarit B. Bhaduri

Materials 2020, 13(16), 3501; https://doi.org/10.3390/ma13163501 - 8 Aug 2020

Cited by 12 | Viewed by 3938

Abstract

This article reports, for the first time, the ‘proof-of-concept’ results on magnetic monetite (CaHPO₄)-based calcium phosphate cements (CPCs) compositions developed for the hyperthermia treatment of bone tumors. Hyperthermia involves the heating of a tumor within a temperature range of 40–45 °C, inducing apoptosis in the tumor cells. This process holds promising potential in the field of cancer treatment and has been proven to be more effective than conventional therapeutics. Hence, we aimed to develop cement compositions that are capable of the hyperthermia treatment of bone tumors. To achieve that central goal, we incorporated iron oxide (Fe₃O₄), a ferromagnetic material, into monetite and hypothesized that, upon the application of a magnetic field, magnetite will generate heat and ablate the tumor cells near the implantation site. The results confirmed that an optimized content of magnetite incorporation in monetite can generate heat in the range of 40–45 °C upon the application of a magnetic field. Furthermore, the compositions were bioactive and cytocompatible with an osteoblastic cell line. Full article

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18 pages, 1254 KiB

Open AccessArticle

The Monetite Structure Probed by Advanced Solid-State NMR Experimentation at Fast Magic-Angle Spinning

by Yang Yu, Baltzar Stevensson, Michael Pujari-Palmer, Hua Guo, Håkan Engqvist and Mattias Edén

Int. J. Mol. Sci. 2019, 20(24), 6356; https://doi.org/10.3390/ijms20246356 - 17 Dec 2019

Cited by 19 | Viewed by 4519

Abstract

We present a solid-state nuclear magnetic resonance (NMR) spectroscopy study of the local

^{31}

P and

^{1}

H environments in monetite [CaHPO

_{4}

; dicalcium phosphate anhydrous (DCPA)], as well as their relative spatial proximities. Each of the three

^{1}

H NMR peaks [...] Read more.

We present a solid-state nuclear magnetic resonance (NMR) spectroscopy study of the local

^{31}

P and

^{1}

H environments in monetite [CaHPO

_{4}

; dicalcium phosphate anhydrous (DCPA)], as well as their relative spatial proximities. Each of the three

^{1}

H NMR peaks was unambiguously assigned to its respective crystallographically unique H site of monetite, while their pairwise spatial proximities were probed by homonuclear

^{1}

H–

^{1}

H double quantum–single quantum NMR experimentation under fast magic-angle spinning (MAS) of 66 kHz. We also examined the relative

^{1}

H–

^{31}

P proximities among the inequivalent {P1, P2} and {H1, H2, H3} sites in monetite; the corresponding shortest internuclear

^{1}

H–

^{31}

P distances accorded well with those of a previous neutron diffraction study. The NMR results from the monetite phase were also contrasted with those observed from the monetite component present in a pyrophosphate-bearing calcium phosphate cement, demonstrating that while the latter represents a disordered form of monetite, it shares all essential local features of the monetite structure. Full article

(This article belongs to the Special Issue NMR Characterization of Amorphous and Disordered Materials)

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15 pages, 12848 KiB

Open AccessArticle

A Novel Class of Injectable Bioceramics That Glue Tissues and Biomaterials

by Michael Pujari-Palmer, Hua Guo, David Wenner, Hélène Autefage, Christopher D. Spicer, Molly M. Stevens, Omar Omar, Peter Thomsen, Mattias Edén, Gerard Insley, Philip Procter and Hakan Engqvist

Materials 2018, 11(12), 2492; https://doi.org/10.3390/ma11122492 - 7 Dec 2018

Cited by 45 | Viewed by 8896

Abstract

Calcium phosphate cements (CPCs) are clinically effective void fillers that are capable of bridging calcified tissue defects and facilitating regeneration. However, CPCs are completely synthetic/inorganic, unlike the calcium phosphate that is found in calcified tissues, and they lack an architectural organization, controlled assembly mechanisms, and have moderate biomechanical strength, which limits their clinical effectiveness. Herein, we describe a new class of bioinspired CPCs that can glue tissues together and bond tissues to metallic and polymeric biomaterials. Surprisingly, alpha tricalcium phosphate cements that are modified with simple phosphorylated amino acid monomers of phosphoserine (PM-CPCs) bond tissues up to 40-fold stronger (2.5–4 MPa) than commercial cyanoacrylates (0.1 MPa), and 100-fold stronger than surgical fibrin glue (0.04 MPa), when cured in wet-field conditions. In addition to adhesion, phosphoserine creates other novel properties in bioceramics, including a nanoscale organic/inorganic composite microstructure, and templating of nanoscale amorphous calcium phosphate nucleation. PM-CPCs are made of the biocompatible precursors calcium, phosphate, and amino acid, and these represent the first amorphous nano-ceramic composites that are stable in liquids. Full article

(This article belongs to the Section Biomaterials)

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