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Guicherd M, Ben Khaled M, Guéroult M, Nomme J, Dalibey M, Grimaud F, Alvarez P, Kamionka E, Gavalda S, Noël M, Vuillemin M, Amillastre E, Labourdette D, Cioci G, Tournier V, Kitpreechavanich V, Dubois P, André I, Duquesne S, Marty A. An engineered enzyme embedded into PLA to make self-biodegradable plastic. Nature 2024; 631:884-890. [PMID: 39020178 DOI: 10.1038/s41586-024-07709-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/12/2024] [Indexed: 07/19/2024]
Abstract
Plastic production reached 400 million tons in 2022 (ref. 1), with packaging and single-use plastics accounting for a substantial amount of this2. The resulting waste ends up in landfills, incineration or the environment, contributing to environmental pollution3. Shifting to biodegradable and compostable plastics is increasingly being considered as an efficient waste-management alternative4. Although polylactide (PLA) is the most widely used biosourced polymer5, its biodegradation rate under home-compost and soil conditions remains low6-8. Here we present a PLA-based plastic in which an optimized enzyme is embedded to ensure rapid biodegradation and compostability at room temperature, using a scalable industrial process. First, an 80-fold activity enhancement was achieved through structure-based rational engineering of a new hyperthermostable PLA hydrolase. Second, the enzyme was uniformly dispersed within the PLA matrix by means of a masterbatch-based melt extrusion process. The liquid enzyme formulation was incorporated in polycaprolactone, a low-melting-temperature polymer, through melt extrusion at 70 °C, forming an 'enzymated' polycaprolactone masterbatch. Masterbatch pellets were integrated into PLA by melt extrusion at 160 °C, producing an enzymated PLA film (0.02% w/w enzyme) that fully disintegrated under home-compost conditions within 20-24 weeks, meeting home-composting standards. The mechanical and degradation properties of the enzymated film were compatible with industrial packaging applications, and they remained intact during long-term storage. This innovative material not only opens new avenues for composters and biomethane production but also provides a feasible industrial solution for PLA degradation.
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Affiliation(s)
- M Guicherd
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- Carbios, Clermont-Ferrand, France
| | - M Ben Khaled
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - M Guéroult
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- Carbios, Clermont-Ferrand, France
| | - J Nomme
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | | | | | - P Alvarez
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - E Kamionka
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - S Gavalda
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- Carbios, Clermont-Ferrand, France
| | - M Noël
- Carbiolice, Clermont-Ferrand, France
| | - M Vuillemin
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - E Amillastre
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - D Labourdette
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - G Cioci
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | | | - V Kitpreechavanich
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - P Dubois
- Center of Innovation and Research in Materials & Polymers, University of Mons, Mons, Belgium
| | - I André
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France.
| | - S Duquesne
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - A Marty
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France.
- Carbios, Clermont-Ferrand, France.
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Greene AF, Vaidya A, Collet C, Wade KR, Patel M, Gaugler M, West M, Petcu M, Parker K. 3D-Printed Enzyme-Embedded Plastics. Biomacromolecules 2021; 22:1999-2009. [PMID: 33870685 DOI: 10.1021/acs.biomac.1c00105] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A simple and environmentally friendly approach toward the thermoplastic processing of rapidly degradable plastic-enzyme composites using three-dimensional (3D) printing techniques is described. Polycaprolactone/Amano lipase (PCL/AL) composite films (10 mm × 10 mm; height [h] = ∼400 μm) with an AL loading of 0.1, 1.0, and 5.0% were prepared via 3D printing techniques that entail direct mixing in the solid state and thermal layer-by-layer extrusion. It was found that AL can tolerate in situ processing temperatures up to 130 °C in the solid-state for 60 min without loss of enzymatic activity. The composites were degraded in phosphate buffer (8 mg/mL, composite to buffer) for 7 days at 37 °C and the resulting average percent total weight loss (WLavg %) was found to be 5.2, 92.9, and 100%, for the 0.1, 1.0, and 5.0% films, respectively. The degradation rates of PCL/AL composites were found to be faster than AL applied externally in the buffer. Thicker PCL/AL 1.0% films (10 mm × 10 mm; h = ∼500 μm) were also degraded over a 7 day period to examine how the weight loss occurs over time with 3.0, 18.1, 36.4, 46.4, and 70.2% weight loss for days 1, 2, 3, 4, and 7, respectively. Differential scanning calorimetry (DSC) analysis shows that the film's percent crystallinity (Dxtal%) increases over time with Dxtal% = 46.5 for day 0 and 53.1% for day 7. Scanning electron microscopy (SEM) analysis found that film erosion begins at the surface and that water can penetrate the interior via surface pores activating the enzymes embedded in the film. Controlled release experiments utilizing dye-loaded PCL/AL/dye (AL = 1.0%; dye = 0.1%) composites were degraded over a 7 day period with the bulk of the dye released by the fourth day. The PCL/AL multimaterial objects containing AL-resistant polylactic acid (PLA) were also printed and degraded to demonstrate the application of this material on more complex structures.
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Affiliation(s)
- Angelique F Greene
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Alankar Vaidya
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Christophe Collet
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Kelly R Wade
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Meeta Patel
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Marc Gaugler
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Mark West
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Miruna Petcu
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
| | - Kate Parker
- Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand
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Tong X, Shi Z, Xu L, Lin J, Zhang D, Wang K, Li Y, Wen C. Degradation behavior, cytotoxicity, hemolysis, and antibacterial properties of electro-deposited Zn-Cu metal foams as potential biodegradable bone implants. Acta Biomater 2020; 102:481-492. [PMID: 31740321 DOI: 10.1016/j.actbio.2019.11.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/12/2019] [Accepted: 11/12/2019] [Indexed: 11/25/2022]
Abstract
Zinc (Zn) alloys have attracted much attention for biomedical applications due to their biodegradability, biocompatibility, and biological functionalities. Zn alloy foams have high potential to be used as regenerative medical implants by virtue of their porous structure, which allows new bone tissue ingrowth, their low elastic modulus approximating that of natural bone, and their biodegradation, which eliminates the need for follow-up surgery to remove the implants after bone tissue healing. In this context, a biodegradable Zn-Cu foam was fabricated by electrochemical deposition on a foamed Cu template and given a subsequent diffusion heat treatment. The microstructure, mechanical properties, degradation behavior, toxicity, hemolysis percentages, and antibacterial effects of the Zn-Cu foams were assessed for biomedical applications. The Zn-Cu foams exhibited a yield strength of ~12.1 MPa, a plateau strength of 16.8 MPa, and a strain over 50% under compression tests. The corrosion rate of the Zn-Cu foams measured by electrochemical polarization testing was 0.18 mm/y. The Zn-Cu foams showed good blood compatibility with a hemolysis percentage of less than 5%. Cytotoxicity assessment indicated that a 100% concentration of the Zn-Cu foam extract showed clear cytotoxicity against MC3T3-E1 osteoblast cells, but a 12.5% concentration of the extract showed > 90% cell viability. Moreover, the Zn-Cu foams showed good antibacterial effects. STATEMENT OF SIGNIFICANCE: This work reportsa biodegradable Zn-Cu foam with high mechanical strength and ductility, suitable degradation rate, good antibacterial capacity, and good hemolysis property and biocompatibility. The Zn-Cu foam exhibited a yield strength of ~12.1 MPa, a plateau strength of 16.8 MPa, and a strain over 50% under compression tests. The corrosion rate of the Zn-Cu foam measured by electrochemical polarization testing was 0.18 mm/y in Hanks' Solutions. The Zn-Cu foam showed good blood compatibility with a hemolysis percentage of less than 5%. Cytotoxicity assessment indicated that a 12.5% concentration of the foam extract showed > 90% cell viability. Moreover, the Zn-Cu foam showed good antibacterial effects against S. aureus.
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Affiliation(s)
- Xian Tong
- Department of Material Engineering, Zhejiang Industry & Trade Vocational College, Wenzhou 325003, China; School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China
| | - Zimu Shi
- Department of Material Engineering, Zhejiang Industry & Trade Vocational College, Wenzhou 325003, China; Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
| | - Linchao Xu
- Department of Material Engineering, Zhejiang Industry & Trade Vocational College, Wenzhou 325003, China
| | - Jixing Lin
- Department of Material Engineering, Zhejiang Industry & Trade Vocational College, Wenzhou 325003, China; School of Physics and Optoelectronics Xiangtan University, Xiangtan 411105, China.
| | - Dechuang Zhang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China
| | - Kun Wang
- Department of Material Engineering, Zhejiang Industry & Trade Vocational College, Wenzhou 325003, China
| | - Yuncang Li
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Cuie Wen
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia.
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