Highly porous bioceramic scaffolds are widely used as bone substitutes in many applications. However, the use of bioceramics is often limited to hard tissues due to the risk of potential soft tissue calcification. A further limitation of highly porous bioceramic scaffolds is their poor mechanical stability, manifested by their tendency to break under stress. In our study, highly porous CaP-based scaffolds were prepared via freeze-casting with longitudinal and oriented pores ranging from 10 to 20 μm and a relative porosity of ∼70%. The resulting scaffolds achieved a flexural strength of 10.6 ± 2.7 MPa, which, in conjunction with their favorable bioactivity, made them suitable for in vivo testing. The prepared scaffolds were subcutaneously implanted in rats for two distinct periods: 6 weeks and 6 months, respectively. The subsequent development of fibrous tissue and involvement of myofibroblasts, newly formed vessels, and macrophages were observed, with notable changes in spatial and temporal distributions within the implantation. The absence of calcification in the surrounding soft tissue, as a result of the narrow pore geometry, indicates the opportunity to tailor the scaffold behavior for soft tissue regeneration.

Central European Institute of Technology Brno University of Technology Purkynova 656 123 612 00 Brno Czech Republic

Department of Chemistry Biochemistry Mendel University in Brno Trida Generala Piky 1999 5 613 00 Brno Czech Republic

Department of Physics of Condensed Matter Faculty of Physics University of Seville Avenue de la Reina Mercedes S N Seville 41012 Spain

Department of Radiobiology Faculty of Military Health Science University of Defence Trebesska 1575 500 01 Hradec Kralove Czech Republic

Department of Toxicology and Military Pharmacy Faculty of Military Health Science University of Defence Trebesska 1575 500 01 Hradec Kralove Czech Republic

Institute of Physics of Materials Academy of Science of the Czech Republic Zizkova 513 22 616 62 Brno Czech Republic

Institute of Structural and Functional Ceramics Montatuniversität Leoben Peter Tunner Strasse 5 8700 Leoben Austria

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Vallet-Regí M.; Salinas A. J.. Ceramics as bone repair materials. In Bone Repair Biomaterials; Elsevier, 2019; pp 141–178.10.1016/B978-0-08-102451-5.00006-8. DOI

Jeong J.; Kim J. H.; Shim J. H.; Hwang N. S.; Heo C. Y. Bioactive calcium phosphate materials and applications in bone regeneration. Biomater. Res. 2019, 23, 4.10.1186/s40824-018-0149-3. PubMed DOI PMC

Eliaz N.; Metoki N. Calcium Phosphate Bioceramics: A Review of Their History, Structure, Properties, Coating Technologies and Biomedical Applications. Materials 2017, 10, 334.10.3390/ma10040334. PubMed DOI PMC

Karageorgiou V.; Kaplan D. Porosity of 3D biomaterial scaffolds and osteogenesis. Biomaterials 2005, 26, 5474–5491. 10.1016/j.biomaterials.2005.02.002. PubMed DOI

Deville S. Freeze-Casting of Porous Ceramics: A Review of Current Achievements and Issues. Adv. Eng. Mater. 2008, 10, 155–169. 10.1002/adem.200700270. DOI

Deville S.; Saiz E.; Tomsia A. P. Freeze casting of hydroxyapatite scaffolds for bone tissue engineering. Biomaterials 2006, 27, 5480–5489. 10.1016/j.biomaterials.2006.06.028. PubMed DOI

Shao G.; Hanaor D. A. H.; Shen X.; Gurlo A. Freeze Casting: From Low-Dimensional Building Blocks to Aligned Porous Structures—A Review of Novel Materials, Methods, and Applications. Adv. Mater. 2020, 32, 1907176.10.1002/adma.201907176. PubMed DOI

Deville S. Freeze-Casting of Porous Biomaterials: Structure, Properties and Opportunities. Materials 2010, 3, 1913–1927. 10.3390/ma3031913. DOI

Deville S.; Meille S.; Seuba J. A meta-analysis of the mechanical properties of ice-templated ceramics and metals. Sci. Technol. Adv. Mater. 2015, 16, 043501.10.1088/1468-6996/16/4/043501. PubMed DOI PMC

Roleček J.; Pejchalová L.; Martínez-Vázquez F.; González P. M.; Salamon D. .. Bioceramic scaffolds fabrication: Indirect 3D printing combined with ice-templating vs. robocasting. J. Eur. Ceram. Soc. 2019, 39, 1595–1602. 10.1016/j.jeurceramsoc.2018.12.006. DOI

Munch E.; Saiz E.; Tomsia A. P.; Deville S. Architectural Control of Freeze-Cast Ceramics Through Additives and Templating. J. Am. Ceram. Soc. 2009, 92, 1534–1539. 10.1111/j.1551-2916.2009.03087.x. DOI

Barba A.; Diez-Escudero A.; Maazouz Y.; Rappe K.; Espanol M.; Montufar E. B.; Bonany M.; Sadowska J. M.; Guillem-Marti J.; Öhman-Mägi C.; et al. Osteoinduction by Foamed and 3D-Printed Calcium Phosphate Scaffolds: Effect of Nanostructure and Pore Architecture. ACS Appl. Mater. 2017, 9, 41722–41736. 10.1021/acsami.7b14175. PubMed DOI

C Chow L. Next generation calcium phosphate-based biomaterials. Dent. Mater. J. 2009, 28, 1–10. 10.4012/dmj.28.1. PubMed DOI PMC

Zhou D.; Qi C.; Chen Y.-X.; Zhu Y.-J.; Sun T.-W.; Chen F.; Zhang C. Q. Comparative study of porous hydroxyapatite/chitosan and whitlockite/chitosan scaffolds for bone regeneration in calvarial defects. Int. J. Nanomed. 2017, 12, 2673–2687. 10.2147/IJN.S131251. PubMed DOI PMC

Wieringa P. A.; Pinho A. R. G. d.; Micera S.; Wezel R. J. A. v.; Moroni L. Biomimetic Architectures for Peripheral Nerve Repair: A Review of Biofabrication Strategies. Adv. Healthcare Mater. 2018, 7, e170116410.1002/adhm.201701164. PubMed DOI

Toth J. M.; Hirthe W. M.; Hubbard W. G.; Brantley W. A.; Lynch K. L. Determination of the ratio of HA/TCP mixtures by x-ray diffraction. J. Appl. Biomater. 1991, 2, 37–40. 10.1002/jab.770020106. DOI

Kokubo T.; Takadama H. How useful is SBF in predicting in vivo bone bioactivity?. Biomaterials 2006, 27, 2907–2915. 10.1016/j.biomaterials.2006.01.017. PubMed DOI

Pejchal J.; Novotny J.; Marak V.; Osterreicher J.; Tichy A.; Vávrová J.; Šinkorová Z.; Zárybnická L.; Novotná E.; Chládek J.; et al. Activation of p38 MAPK and expression of TGF-β1 in rat colon enterocytes after whole body γ-irradiation. Int. J. Radiat. Biol. 2012, 88, 348–358. 10.3109/09553002.2012.654044. PubMed DOI

Hulbert S. F.; Young F. A.; Mathews R. S.; Klawitter J. J.; Talbert C. D.; Stelling F. H. Potential of ceramic materials as permanently implantable skeletal prostheses. J. Biomed. Mater. Res. 1970, 4, 433–456. 10.1002/jbm.820040309. PubMed DOI

Murphy C. M.; Haugh M. G.; O’Brien F. J. The effect of mean pore size on cell attachment, proliferation and migration in collagen–glycosaminoglycan scaffolds for bone tissue engineering. Biomaterials 2010, 31, 461–466. 10.1016/j.biomaterials.2009.09.063. PubMed DOI

Altinova H.; Achenbach P.; Palm M.; Katona I.; Hermans E.; Clusmann H.; Weis J.; Brook G. A. Characterization of a Novel Aspect of Tissue Scarring Following Experimental Spinal Cord Injury and the Implantation of Bioengineered Type-I Collagen Scaffolds in the Adult Rat: Involvement of Perineurial-like Cells?. Int. J. Mol. Sci. 2022, 23, 3221.10.3390/ijms23063221. PubMed DOI PMC

Habibovic P.; Sees T. M.; Doel M. A. v. d.; Blitterswijk C. A.; Groot K. Osteoinduction by biomaterials—Physicochemical and structural influences. J. Biomed. Mater. Res., Part A 2006, 77, 747–762. 10.1002/jbm.a.30712. PubMed DOI

Habibovic P.; Bassett D. C.; Doillon C. J.; Gerard C.; Mckee M. D.; Barralet J. E. Collagen Biomineralization In Vivo by Sustained Release of Inorganic Phosphate Ions. Adv. Mater. 2010, 22, 1858–1862. 10.1002/adma.200902778. PubMed DOI

Aza P. N. d.; Santos C.; Pazo A.; Aza S.; Cuscó R.; Artús L. Vibrational Properties of Calcium Phosphate Compounds. 1. Raman Spectrum of β-Tricalcium Phosphate. Chem. Mater. 1997, 9, 912–915. 10.1021/cm960425d. DOI

Aza P. N. D.; Guitián F.; Santos C.; Aza S.; Cuscó R.; et al. Vibrational Properties of Calcium Phosphate Compounds. 2. Comparison between Hydroxyapatite and β-Tricalcium Phosphate. Chem. Mater. 1997, 9, 916–922. 10.1021/cm9604266. DOI

Ou S.-F.; Chiou S.-Y.; Ou K.-L. Phase transformation on hydroxyapatite decomposition. Ceram. Int. 2013, 39, 3809–3816. 10.1016/j.ceramint.2012.10.221. DOI

Chu K.-T.; Ou S.-F.; Chen S.-Y.; Chiou S.-Y.; Chou H.-H.; Ou K. L. Research of phase transformation induced biodegradable properties on hydroxyapatite and tricalcium phosphate based bioceramic. Ceram. Int. 2013, 39, 1455–1462. 10.1016/j.ceramint.2012.07.089. DOI

Pejchalová L.; Roleček J.; Salamon D. Why freeze-casting brings different phase composition of calcium phosphates?. Open Ceram. 2021, 7, 100161.10.1016/j.oceram.2021.100161. DOI

Paredes C.; Roleček J.; Pejchalová L.; Miranda P.; Salamon D. Impact of residual carbon after DLP and SPS-Sintering on compressive strength and in-VITRO bioactivity of calcium phosphate scaffolds. Open Ceram. 2022, 11, 100281.10.1016/j.oceram.2022.100281. DOI

Paredes C.; Roleček J.; Miranda P. Improving the strength of β-TCP scaffolds produced by Digital Light Processing using two-step sintering. J. Eur. Ceram. Soc. 2024, 44, 2571–2580. 10.1016/j.jeurceramsoc.2023.11.028. DOI

Fan X.; Case E. D.; Gheorghita I.; Baumann M. J. Weibull modulus and fracture strength of highly porous hydroxyapatite. J. Mech. Behav. Biomed. Mater. 2013, 20, 283–295. 10.1016/j.jmbbm.2013.01.031. PubMed DOI

Osuchukwu O. A.; Salihi A.; Abdullahi I.; Etinosa P. O.; Obada D. O. Weibull modulus of a novel mixture of natural hydroxyapatite materials produced from biowastes. Results Mater. 2023, 18, 100394.10.1016/j.rinma.2023.100394. DOI

Hench L. L. Bioceramics: From Concept to Clinic. J. Am. Ceram. Soc. 1991, 74, 1487–1510. 10.1111/j.1151-2916.1991.tb07132.x. DOI

Bartlett R. D.; Eleftheriadou D.; Evans R.; Choi D.; Phillips J. B. Mechanical properties of the spinal cord and brain: Comparison with clinical-grade biomaterials for tissue engineering and regenerative medicine. Biomaterials 2020, 258, 120303.10.1016/j.biomaterials.2020.120303. PubMed DOI

Sadowska J. M.; Ginebra M.-P. Inflammation and biomaterials: role of the immune response in bone regeneration by inorganic scaffolds. J. Mater. Chem. B 2020, 8, 9404–9427. 10.1039/D0TB01379J. PubMed DOI

Kargozar S.; Mozafari M.; Ghodrat S.; Fiume E.; Baino F. Copper-containing bioactive glasses and glass-ceramics: From tissue regeneration to cancer therapeutic strategies. Mater. Sci. Eng.: C Mater. Biol. Appl. 2021, 121, 111741.10.1016/j.msec.2020.111741. PubMed DOI

Maruoka H.; Hasegawa T.; Yoshino H.; Abe M.; Haraguchi-Kitakamae M.; Yamamoto T.; Hongo H.; Nakanishi K.; Nasoori A.; Nakajima Y.; et al. Immunolocalization of endomucin-reactive blood vessels and α-smooth muscle actin-positive cells in murine nasal conchae. J. Oral Biosci. 2022, 64, 337–345. 10.1016/j.job.2022.05.001. PubMed DOI

Davies J. E.; Matta R.; Mendes V. C.; Carvalho P. S. Development, characterization and clinical use of a biodegradable composite scaffold for bone engineering in oro-maxillo-facial surgery. Organogenesis 2014, 6, 161–166. 10.4161/org.6.3.12392. PubMed DOI PMC

Huang Y.; Wu C.; Zhang X.; Chang J.; Dai K. Regulation of immune response by bioactive ions released from silicate bioceramics for bone regeneration. Acta Biomater. 2018, 66, 81–92. 10.1016/j.actbio.2017.08.044. PubMed DOI