Accessible Unlicensed Requires Authentication Published by De Gruyter November 16, 2021

Improvement of Mechanical and Biological Properties of PLA/HNT Scaffolds Fabricated by Foam Injection Molding: Skin Layer Effect and Laser Texturing

M. Eryildiz, M. Altan and S. Odabas


Polylactic acid (PLA) is one of the important materials for orthopedic regenerative engineering applications due to its biodegradability and biocompatibility. Nonetheless, PLA may show insufficient mechanical strength for some bone replacement applications. Halloysite nanotube (HNT) is one of the non-toxic, biocompatible reinforcement for improving mechanical and biological properties of PLA for tissue engineering applications. In this study, PLA/HNT scaffolds were prepared by chemical foam injection molding process. Laser surface texturing was applied on the skin layer of the injection molded scaffolds to enhance the cell viability and hydrophilicity of PLA. The effects of HNT concentration on cell morphology, mechanical and thermal properties, cell viability and biodegradation profile of the scaffolds were studied. The results demonstrated that cell viability increased by 43% in PLA/HNT scaffolds compared to neat PLA. Hydrophilicity of the scaffolds that have thick skin layer was enhanced by the laser surface texturing in two different designs and consequently, cell viability increased about 16%. Surface roughness measurements and water contact angle measurements have verified this result.

Meltem Eryildiz, Department of Mechanical Engineering, Yildiz Technical University, 34349, Besiktas, Istanbul, Turkey


This work was supported by Research Fund of the Yildiz Technical University [Project Number: FDK-2018-3362].


Alakrach, A. M., Noriman, N. Z., AlSaadi, M. A., Sam, S. T., Pasbakhsh, P., Dahham, O. S. and Shayfull, Z., “Thermal Properties of PLA/HNTs Composites: Effect of Different Halloysite Nanotube", AIP Conf. Proc., 2030, 1–7 (2018), DOI:10.1063/1.506669310.1063/1.5066693Search in Google Scholar

Ameli, A., Nofar, M., Jahani, D., Rizvi, G. and Park, C. B., “Development of High Void Fraction Polylactide Composite Foams Using Injection Molding: Crystallization and Foaming Behaviors", Chem. Eng. J., 262, 78–87 (2015), DOI:10.1016/j.cej.2014.09.08710.1016/j.cej.2014.09.087Search in Google Scholar

Belaud, V., Valette, S., Stremsdoerfer, G., Bigerelle, M. and Benayoun, S., “Wettability versus Roughness: Multi-Scales Approach", Tribol. Int., 82, 343–349 (2015), DOI:10.1016/j.triboint.2014.07.00210.1016/j.triboint.2014.07.002Search in Google Scholar

Cavallaro, G., Donato, D. I., Lazzara, G. and Milioto, S. J., “Films of Halloysite Nanotubes Sandwiched between Two Layers of Biopolymer: From the Morphology to the Dielectric, Thermal, Transparency, and Wettability Properties", J. Phys. Chem. C, 115(42), 20491–20498 (2011), DOI:10.1021/jp207261r10.1021/jp207261rSearch in Google Scholar

Chen, Y., Geever, L. M., Killion, J. A., Lyons, J.G., Higginbotham, C. L. and Devine, D. M., “Halloysite Nanotube Reinforced Polylactic Acid Composite", Polym. Compos., 38, 2166–2173 (2005), DOI:10.1002/pc.2379410.1002/pc.23794Search in Google Scholar

Chow, W. S., Tham, W. L., Poh, B. T. and Mohd Ishak, Z. A., “Mechanical and Thermal Oxidation Behavior of Poly(lactic acid)/Halloysite Nanotube Nanocomposites Containing N,N’-Ethylenebis(Stearamide) and SEBS-g-MA", J. Polym. Environ., 26, 2973–2982 (2018), DOI:10.1007/s10924-018-1186-710.1007/s10924-018-1186-7Search in Google Scholar

Corre, Y. M., Maazouz, A., Duchet, J. and Reignier, J., “Batch Foaming of Chain Extended PLA with Supercritical CO2: Influence of the Rheological Properties and the Process Parameters on the Cellular Structure", J. Supercrit. Fluids, 58(1), 177–188 (2011), DOI:10.1016/j.supflu.2011.03.00610.1016/j.supflu.2011.03.006Search in Google Scholar

Daskalova, A., Ostrowska, B., Zhelyazkova, A., Święszkowski, W., Trifonov, A., Declercq, H., Nathala, C., Szlazak, K., Lojkowski, M., Husinsky, W. and Buchvarov, I., “Improving Osteoblasts Cells Proliferation via Femtosecond Laser Surface Modification of 3D-Printed Poly-e-Caprolactone Scaffolds for Bone Tissue Engineering Applications", Appl. Phys. A, 124, 1–15 (2018), DOI:10.1007/s00339-018-1831-y10.1007/s00339-018-1831-ySearch in Google Scholar

Dong, Y., Marshall, J., Haroosh, H. J., Moghadam, S. M., Liu, D., Qi, X. and Lau, K., “Polylactic Acid (PLA)/Halloysite Nanotube (HNT) Composite Mats: Influence of HNT Content and Modification", Composites Part A, 76, 28–36 (2015), DOI:10.1016/j.compositesa.2015.05.01110.1016/j.compositesa.2015.05.011Search in Google Scholar

Eryildiz, M., Altan M., “Fabrication of Polylactic Acid/Halloysite Nanotube Scaffolds by Foam Injection Molding for Tissue Engineering", Polym. Compos., 41, 757–767 (2020), DOI:10.1002/pc.2540610.1002/pc.25406Search in Google Scholar

Gomes, M. E., Ribeiro, A. S., Malafaya, P. B., Reis, R. L. and Cunha, A. M., “A New Approach Based on Injection Moulding to Produce Biodegradable Starch-Based Polymeric Scaffolds: Morphology, Mechanical and Degradation Behaviour", Biomaterials, 22, 883–889 (2001), DOI:10.1016/S0142-9612(00)00211-810.1016/S0142-9612(00)00211-8Search in Google Scholar

Gómez-Pachón, E. Y., Vera-Graziano, R. and Raul, M., “Structure of Poly(lactic-acid) PLA Nanofibers Scaffolds Prepared by Electro-spinning", IOP Conf. Ser. Mater. Sci. Eng., 59, 1–9 (2014), DOI:10.1088/1757-899X/59/1/01200310.1088/1757-899X/59/1/012003Search in Google Scholar

Guo, J., Qiao, J. and Zhang, X., “Effect of an Alkalized-Modified Halloysite on PLA Crystallization, Morphology, Mechanical, and Thermal Properties of PLA/Halloysite Nanocomposites", J. Appl. Polym. Sci., 133, 1–8 (2016), DOI:10.1002/app. 4427210.1002/app. 44272Search in Google Scholar

Guo, Z., Yang, C., Zhou, Z., Chen, S. and Li, F., “Characterization of Biodegradable Poly(lactic acid) Porous Scaffolds Prepared Using Selective Enzymatic Degradation for Tissue Engineering", RSC Adv., 7, 34063–34070 (2017), DOI:10.1039/C7RA03574H10.1039/C7RA03574HSearch in Google Scholar

Havaldar, R., Pilli, S. C. and Putti, B. B., “Insights into the Effects of Tensile and Compressive Loadings on Human Femur Bone", Adv. Biomed. Res., 3, 1–7 (2014), DOI:10.4103/2277-9175.129375/10.4103/2277-9175.129375/Search in Google Scholar

Hong, Y., Chen, L., Song, G., Bassir, D., Cheng, S., Shi, X., Liu, H. and Tang, G., “Effect of in situ Reaction on Thermal and Mechanical Properties of Polylactide/Talc Composites", Polym. Compos., 39, 1618–1625 (2018), DOI:10.1002/pc.2453010.1002/pc.24530Search in Google Scholar

Ibrahim, N., Jollands, M. and Parthasarathy, R., “Morphology and Mechanical Properties of Polylactide/Montmorillonite Composites", J. Phys.: Conf. Ser., 1349, 012048 (2019), DOI:10.1088/1742-6596/1349/1/01204810.1088/1742-6596/1349/1/012048Search in Google Scholar

Kaseem, M., Hamad, K. and Ur Rehman, Z., “Review of Recent Advances in Polylactic Acid/TiO2 Composites", Materials, 12, 3659 (2019), DOI:10.3390/ma1222365910.3390/ma12223659Search in Google Scholar

Kaygusuz, I., Kaynak, C., “Influences of Halloysite Nanotubes on Crystallisation Behaviour of Polylactide. Plastics", Rubber Compos., 44, 41–49 (2015), DOI:10.1179/1743289814Y.000000011610.1179/1743289814Y.0000000116Search in Google Scholar

Ke, T. K., Sun, X. S., “Starch, Poly(lactic acid), and Poly(vinyl alcohol) Blends", J. Polym. Environ., 11, 7–14 (2003), DOI:10.1023/A:102387522745010.1023/A:1023875227450Search in Google Scholar

Larsen, A., Neldin, C., “Physical Foaming of Poly(lactic acid)-Processing and Foam Properties", Polym. Eng. Sci., 53, 941–949 (2012), DOI:10.1002/pen.2334110.1002/pen.23341Search in Google Scholar

Lawrence, J., Li, L., “Modification of the Wettability Characteristics of Polymethyl Methacrylate (PMMA) by Means of CO2, Nd:YAG, Excimer and High Power Diode Laser Radiation", Mater. Sci. Eng. A, 303, 142–149 (2001), DOI:10.1016/S0921-5093(00)01851-710.1016/S0921-5093(00)01851-7Search in Google Scholar

Li, Z., Ramay, H. R., Hauch, K. D., Xiao, D. and Zhang, M., “Chitosan–Alginate Hybrid Scaffolds for Bone Tissue Engineering", Biomaterials, 26, 3919–3928 (2005), DOI:10.1016/j.biomaterials.2004.09.06210.1016/j.biomaterials.2004.09.062Search in Google Scholar

Lin, C., Anseth, K. S., “Chapter II.4.3 The Biodegradation of Biodegradable Polymeric Biomaterials", in Biometarials Science an Introduction to Materials in Medicine, Ratner, B. D., Hoffman, A.S., Schoen, F. J., Lemons, J. E. (Eds.), Elsevier, Cambridge, Massachusetts, USA, p. 716–728 (2013), DOI:10.1016/B978-0-08-087780-8.00061-910.1016/B978-0-08-087780-8.00061-9Search in Google Scholar

Liu, M., Zhang, Y. and Zhou, C., “Nanocomposites of Halloysite and Polylactide", Appl. Clay Sci., 75–76, 52–59 (2013), DOI:10.1016/j.clay.2013.02.01910.1016/j.clay.2013.02.019Search in Google Scholar

Liu, W., Wu, X., Ou, Y., Liu, H. and Zhang, C., “Electrically Conductive and Light-Weight Branched Polylactic Acid-Based Carbon Nanotube Foams", e-Polymers, 21, 96–107 (2021), DOI:10.1515/epoly-2021-001310.1515/epoly-2021-0013Search in Google Scholar

Loh, Q. L., Choong, C., “Three-Dimensional Scaffolds for Tissue Engineering Applications: Role of Porosity and Pore Size", Tissue Eng. Part B, 19, 485–502 (2013), DOI:10.1089/ten.TEB.2012.043710.1089/ten.TEB.2012.0437Search in Google Scholar

Lvov, Y., Aerov, A. and Fakhrullin, R., “Clay Nanotube Encapsulation for Functional Biocomposites", Adv. Colloid Interface Sci., 207, 189–198 (2014), DOI:10.1016/j.cis.2013.10.00610.1016/j.cis.2013.10.006Search in Google Scholar

Matsuzaka, K., Walboomers, F., De Ruijter, A. and Jansen, J. A., “Effect of Microgrooved Poly-L-Lactic (PLA) Surfaces on Proliferation, Cytoskeletal Organization, and Mineralized Matrix Formation of Rat Bone Marrow Cells", Clin. Oral Implants Res., 11, 325–333 (2000), PMid:11168225; DOI:10.1034/j.1600-0501.2000.011004325.x10.1034/j.1600-0501.2000.011004325.xSearch in Google Scholar

Mi, H. Y., Salick, M. R., Jing, X., Jacques, B. R., Crone, W. C., Peng, X. F. and Turng, L. S., “Characterization of Thermoplastic Polyurethane/Polylactic Acid (TPU/PLA) Tissue Engineering Scaffolds Fabricated by Microcellular Injection Molding", Mater. Sci. Eng. C-Mater., 33, 4767–4776 (2013), DOI:10.1016/j.msec.2013.07.037/10.1016/j.msec.2013.07.037/Search in Google Scholar

Mohammadi, M. S., Bureau, M. N. and Nazhat, S. N., “Chapter 11 Poly(lactic acid) (PLA) Biomedical Foams for Tissue Engineering", in Biomedical Foams for Tissue Engineering Applications, Netti, P. A. (Ed.), Elsevier, Cambridge, Massachusetts, USA, p. 313–334 (2014), DOI:10.1533/9780857097033.2.31310.1533/9780857097033.2.313Search in Google Scholar

Murphy, C. M., O’Brien, F. J., “Understanding the Effect of Mean Pore Size on Cell Activity in Collagen-Glycosaminoglycan Scaffolds", Cell Adh. Migr.. 4, 377–381 (2010), DOI:10.4161/cam.4.3.1174710.4161/cam.4.3.11747Search in Google Scholar

Nizar, M. M., Hamzah, M. S. A., Razak, A. B. D. and Nayan, N. H. M., “Thermal Stability and Surface Wettability Studies of Polylactic Acid/Halloysite Nanotube Nanocomposite Scaffold for Tissue Engineering Studies", IOP Conf. Ser. Mater. Sci. Eng., 318, 1–9 (2018), DOI:10.1088/1757-899X/318/1/01200610.1088/1757-899X/318/1/012006Search in Google Scholar

Nofar, M., “Effects of Nano-/Micro-Sized Additives and the Corresponding Induced Crystallinity on the Extrusion Foaming Behavior of PLA Using Supercritical CO2", Mater. Des., 101, 24–34 (2016), DOI:10.1016/j.matdes.2016.03.14710.1016/j.matdes.2016.03.147Search in Google Scholar

O’Brien, F. J., “Biomaterials & Scaffolds for Tissue Engineering", Mater. Today, 4, 88–95 (2011), DOI:10.1016/S1369-7021(11)70058-X10.1016/S1369-7021(11)70058-XSearch in Google Scholar

Ogata, N., Jimenez, G., Kawai, H. and Ogihara, T., “Structure and Thermal/Mechanical Properties of Poly(L-lactide)-Clay Blend", J. Polym. Sci. B Polym. Phys., 35, 389–396 (1997), DOI:10.1002/(SICI)1099-0488(19970130)35 : 2<389::AID-POLB14>3.0.CO;2-E10.1002/(SICI)1099-0488(19970130)35 : 2<389::AID-POLB14>3.0.CO;2-ESearch in Google Scholar

Oral, A., Tasdelen, M. A., Demirel, A. L. and Yagci, Y., “Poly(cyclohexene oxide)/Clay Nanocomposites by Photoinitiated Cationic Polymerization via Activated Monomer Mechanism", J. Polym. Sci. Pol Chem., 47, 5328–5335 (2009), DOI:10.1002/pola.2358110.1002/pola.23581Search in Google Scholar

Pantani, R., Volpe, V. and Titomanlio, G., “Foam Injection Molding of Poly(lactic acid) with Environmentally Friendly Physical Blowing Agents", J. Mater. Process. Technol., 214, 3098–3107 (2014), DOI:10.1016/j.jmatprotec.2014.07.00210.1016/j.jmatprotec.2014.07.002Search in Google Scholar

Park, J., Lakes, R. S., “Chapter 7 Polymeric Implant Materials", in Biomaterials: An Introduction, Springer, New York, p. 173–205 (2007)Search in Google Scholar

Peinado, V., García, L., Fernández, A. and Castell, P., “Novel Lightweight Foamed Poly(lactic acid) Reinforced with Different Loadings of Functionalised Sepiolite", Compos. Sci. Technol., 101, 17–23 (2014), DOI:10.1016/j.compscitech.2014.06.02510.1016/j.compscitech.2014.06.025Search in Google Scholar

Prashantha, K., Lecouvet, B., Sclavons, M., Lacrampe, M. F. and Krawczak, P., “Poly(lactic acid)/Halloysite Nanotubes Nanocomposites: Structure, Thermal, and Mechanical Properties as a Function of Halloysite Treatment", J. Appl. Polym. Sci., 128, 1895–1903 (2012), DOI:10.1002/app. 3835810.1002/app. 38358Search in Google Scholar

Rodrigues, N., Benning, M., Ferreira, A. M., Dixon, L. and Dalgarno, K., “Manufacture and Characterisation of Porous PLA Scaffolds", Procedia CIRP, 49, 33–38 (2016), DOI:10.1016/j.procir.2015.07.02510.1016/j.procir.2015.07.025Search in Google Scholar

Rytlewski, P., Mróz, W., Z_ enkiewicz, M., Czwartos J. and Budner, B., “Laser Induced Surface Modification of Polylactide", J. Mater. Process. Technol., 212, 1700–1704 (2012), DOI:10.1016/j.jmatprotec.2012.03.01910.1016/j.jmatprotec.2012.03.019Search in Google Scholar

Saha, S., Hayes, W. C., “Instrumented Tensile-Impact Tests of Bone", Exp. Mech., 14, 473–478 (1974), DOI:10.1007/BF0232314710.1007/BF02323147Search in Google Scholar

Shi, X., Zhang, G., Siligardi, C., Ori, G. and Lazzeri, A., “Comparison of Precipitated Calcium Carbonate/Polylactic Acid and Halloysite/ Polylactic Acid Nanocomposites", J. Nanomater., 24, 1–11 (2015), DOI:10.1155/2015/90521010.1155/2015/905210Search in Google Scholar

Siciński, M., Korzeniewska, E., Tomczyk, M., Pawlak, R., Bieliński, D., Gozdek, T., Kałuzińska, K. and Walczak, M., “Laser-Textured Rubbers with Carbon Nanotube Fillers", Polymers, 10, 1–13 (2018), DOI:10.3390/polym1010109110.3390/polym10101091Search in Google Scholar

Silva, R. T., Pasbakhsh, P., Goh, K. L., Chai, S. P. and Chen, J., “Synthesis and Characterisation of Poly(lactic acid)/Halloysite Bionanocomposite Films", J. Compos. Mater., 48, 3705–3717 (2013), DOI:10.1177/002199831351304610.1177/0021998313513046Search in Google Scholar

Takayama, T., Todo, M., “Improvement of Impact Fracture Properties of PLA/PCL Polymer Blend due to LTI Addition", J. Mater. Sci., 41, 4989–4992 (2006), DOI:10.1007/s10853-006-0137-110.1007/s10853-006-0137-1Search in Google Scholar

Thadavirul, N., Pavasant, P. and Supaphol, P., “Development of Polycaprolactone Porous Scaffolds by Combining Solvent Casting, Particulate Leaching, and Polymer Leaching Techniques for Bone Tissue Engineering", J. Biomed. Mater. Res. A, 102, 3379–3392 (2014), DOI:10.1002/jbm.a.3501010.1002/jbm.a.35010Search in Google Scholar

Thavornyutikarn, B., Chantarapanich, N. and Sitthiseripratip, K., “Bone Tissue Engineering Scaffolding: Computer-Aided Scaffolding Techniques", Prog. Biomater., 3, 61–102 (2014), DOI:10.1007/s40204-014-0026-710.1007/s40204-014-0026-7Search in Google Scholar

Therias, S., Murariu, M. and Dubois, P., “Bionanocomposites Based on PLA and Halloysite Nanotubes: From Key Properties to Photo-oxidative Degradation", Polym. Degrad. Stab., 145, 60–69 (2017), DOI:10.1016/j.polymdegradstab.2017.06.00810.1016/j.polymdegradstab.2017.06.008Search in Google Scholar

Valapa, R. B., Pugazhenthi, G., Katiyar, V., “Hydrolytic Degradation Behaviour of Sucrose Palmitate Reinforced Poly(lactic acid) Nanocomposites", Int. J. Biol. Macromol., 89, 70–80 (2016), DOI:10.1016/j.ijbiomac.2016.04.04010.1016/j.ijbiomac.2016.04.040Search in Google Scholar

Volpe, V., Pantani, R., “Foam Injection Molding of Poly(lactic) Acid: Effect of Back Pressure on Morphology and Mechanical Properties", J. Appl. Polym. Sci., 132, 1–8 (2015), DOI:10.1002/app. 4261210.1002/app. 42612Search in Google Scholar

Walthers, C.M., Nazemi, A. K., Patel, S. L.,Wu, B.M. and Dunn, J. C. Y., “The Effect of ScaffoldMacroporosity on Angiogenesis and Cell Survival in Tissue-Engineered Smooth Muscle", Biomaterials, 35, 5129–5137 (2014), DOI:10.1016/j.biomaterials.2014.03.02510.1016/j.biomaterials.2014.03.025Search in Google Scholar

Wang, J., Zhu, W., Zhang, H. and Park, C. B., “Continuous Processing of Low-Density, Microcellular Poly(lactic acid) Foams with Controlled Cell Morphology and Crystallinity", Chem. Eng. Sci., 75, 390–399 (2012), DOI:10.1016/j.ces.2012.02.05110.1016/j.ces.2012.02.051Search in Google Scholar

Wang, N., Zang, Y. J., Ren, G. Z. and Wu, Q. L., “Fabrication and Properties of Porous Scaffolds of PLA-PEG Biocomposite for Bone Tissue Engineering", Mater. Sci. Forum, 789, 130–135 (2014), DOI:10.4028/ in Google Scholar

Wang, X., Nyman, J. S., Dong, X., Leng, H. and Reyes, M., “Fundamental Biomechanics in Bone Tissue Engineering", Synth. Lect. Tissue Eng., 2, 1–225 (2010), DOI:10.2200/S00246ED1 V01Y200912TIS00410.2200/S00246ED1 V01Y200912TIS004Search in Google Scholar

Wang, W., Caetano, G., Ambler, W. S., Blaker, J. J., Frade, M. A., Mandal, P., Diver, C. and Bártolo, P., “Enhancing the Hydrophilicity and Cell Attachment of 3D Printed PCL/Graphene Scaffolds for Bone Tissue Engineering", Materials (Basel), 9, 992 (2016), DOI:10.3390/ma912099210.3390/ma9120992Search in Google Scholar

Wu, W., Cao, X., Zhang, Y. and He, G., “Polylactide/Halloysite Nanotube Nanocomposites: Thermal, Mechanical Properties, and Foam Processing", J. Appl. Polym. Sci., 130, 443–452 (2013), DOI:10.1002/app. 3917910.1002/app. 39179Search in Google Scholar

Yang, Y., Li, X., Zhang, Q., Xia, C., Chen, C., Chen, X. and Yu, P., “Foaming of Poly(lactic acid) with Supercritical CO2: The Combined Effect of Crystallinity and Crystalline Morphology on Cellular Structure", J. Supercrit. Fluids, 145, 122–132 (2019), DOI:10.1016/j.supflu.2018.12.00610.1016/j.supflu.2018.12.006Search in Google Scholar

Zhang, N. W., Wang, Q. F., Ren, J. and Wang, L., “Preparation and Properties of Biodegradable Poly(lactic acid)/Poly(butylene adipate-co-terephthalate) Blend with Glycidyl Methacrylate as Reactive Processing Agent", J. Mater. Sci., 44, 250–256 (2009), DOI:10.1007/s10853-008-3049-410.1007/s10853-008-3049-4Search in Google Scholar

Zhao, G., Schwartz, Z., Wieland, M., Rupp, F., Geis-Gerstorfer, J., Cochran, D. L. and Boyan, B. D., “High Surface Energy Enhances Cell Response to Titanium Substrate Microstructure", J. Biomed. Mater. Res., 74A, 49–58 (2005), DOI:10.1002/jbm.a.3032010.1002/jbm.a.30320Search in Google Scholar

Zhou, C., Yang, K. and Wang, K., “Combination of Fused Deposition Modeling and Gas Foaming Technique to Fabricated Hierarchical Macro/Microporous Polymer Scaffolds", Mater. Des., 109, 415–424 (2016), DOI:10.1016/j.matdes.2016.07.09410.1016/j.matdes.2016.07.094Search in Google Scholar

Received: 2021-01-17
Accepted: 2021-05-20
Published Online: 2021-11-16

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