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Lee PW, Maia J, Pokorski JK. Milling solid proteins to enhance activity after melt-encapsulation. Int J Pharm 2017; 533:254-265. [PMID: 28939464 DOI: 10.1016/j.ijpharm.2017.09.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/06/2017] [Accepted: 09/16/2017] [Indexed: 12/25/2022]
Abstract
Polymeric systems for the immobilization and delivery of proteins have been extensively used for therapeutic and catalytic applications. While most devices have been created via solution based methods, hot melt extrusion (HME) has emerged as an alternative due to the high encapsulation efficiencies and solvent-free nature of the process. HME requires high temperatures and mechanical stresses that can result in protein aggregation and denaturation, but additives and chemical modifications have been explored to mitigate these effects. This study explores the use of solid-state ball milling to decrease protein particle size before encapsulation within poly(lactic-co-glycolic acid) (PLGA) via HME. The impact of milling on particle dispersion, retained enzymatic activity, secondary structure stability, and release was explored for lysozyme, glucose oxidase, and the virus-like particle derived from Qβ to fully understand the impact of milling on protein systems with different sizes and complexities. The results of this study describe the utility of milling to further increase the stability of protein/polymer systems prepared via HME.
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Affiliation(s)
- Parker W Lee
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Case School of Engineering, Cleveland, OH 44106, United States
| | - João Maia
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Case School of Engineering, Cleveland, OH 44106, United States
| | - Jonathan K Pokorski
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Case School of Engineering, Cleveland, OH 44106, United States.
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Wu F, Dai L, Geng L, Zhu H, Jin T. Practically feasible production of sustained-release microspheres of granulocyte-macrophage colony-stimulating factor (rhGM-CSF). J Control Release 2017; 259:195-202. [PMID: 28389408 DOI: 10.1016/j.jconrel.2017.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/25/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
Using recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) as a model drug, the present study demonstrated a practically feasible process to produce polymeric microspheres for sustained-release delivery of protein drugs with preserved integrity. This process is featured with pre-loading proteins into polysaccharide fine particles via a self-standing aqueous-aqueous "emulsion", prior to microencapsulation into the microspheres. The protein drug, rhGM-CSF, was partitioned thermodynamically into a dextran dispersed phase of the aqueous-aqueous emulsion, followed by lyophilization and removal of the polyethylene glycol (PEG) continuous phase (using an organic solvent not penetrating into dextran matrix). The harvested dextran particles were then suspended in a dichloromethane solution of polylatic-co-glyclic acids (PLGA) and emulsified in a polyvinyl alcohol (PVA) and NaCl solution of small volume to form embryonic microspheres. The emulsion was then transferred into a NaCl solution of large volume to extract the organic solvent and harden the embryonic microspheres. The obtained rhGM-CSF microspheres showed a satisfied release profile with the day-to-day variation within 9 folds over the multi-weeks long release period. At the same time, the integrity (defined freedom of aggregates measured by SEC-HPLC) and bioactivity (defined by TF-1 cell proliferation) of the proteins were well preserved. The present formulation process ensured good reproducibility and over 89% protein encapsulation efficiency, and practically feasible to adapt to scaled productions.
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Affiliation(s)
- Fei Wu
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 00240, China
| | - Lili Dai
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 00240, China
| | - Lee Geng
- New Jersey Medical School, Rutgers University, 185 S. Orange Ave., Newark 07103, USA
| | - Hua Zhu
- New Jersey Medical School, Rutgers University, 185 S. Orange Ave., Newark 07103, USA
| | - Tuo Jin
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 00240, China.
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Wang L, Yang Q, Chen Y, Chai Y, Li JJ, Du L, Tan R, Yang S, Tu M, Yu B. A reformative shear precipitation procedure for the fabrication of vancomycin-loaded poly(lactide-co-glycolide) microspheres. J Biomater Appl 2017; 31:995-1009. [PMID: 28068861 DOI: 10.1177/0885328216689199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This study reports the encapsulation of vancomycin, as a model hydrophilic drug, into poly(lactide-co-glycolide) microspheres using a novel reformative shear precipitation procedure. In contrast to the external aqueous phase used in the conventional microencapsulation technique based on emulsion solvent evaporation/extraction, the reformative shear precipitation procedure explored in this study uses a shear medium composed of glycerol as the viscous medium and ethanol as polymer antisolvent, which is relatively immiscible with the hydrophilic drug. This limits drug diffusion and leads to rapid microsphere solidification, which allows a large proportion of the hydrophilic drug to be encapsulated within the microspheres. The influence of various processing parameters, including polymer concentration, volume ratio of ethanol to glycerol in the shear medium, volume of aqueous drug solution, initial drug loading, and injecting rate of the drug-polymer emulsion, on the encapsulation efficiency and characteristics of resulting microspheres were investigated. The morphology and release characteristics, as well as mechanical, in vitro and in vivo behaviour of vancomycin-loaded poly(lactide-co-glycolide) microspheres prepared using the novel procedure were also investigated. The results demonstrated that the reformative shear precipitation procedure could achieve the loading of hydrophilic drugs into poly(lactide-co-glycolide) microspheres with high encapsulation efficiency, and the success of the procedure was largely influenced by the volume ratio of ethanol to glycerol in the shear medium. Vancomycin-loaded poly(lactide-co-glycolide) microspheres prepared using this procedure demonstrated favourable mechanical characteristics, antibacterial activity, and in vivo degradation behaviour which suggested their suitability for use as a sustained delivery system.
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Affiliation(s)
- Lei Wang
- 1 Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Qinmeng Yang
- 1 Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Yirong Chen
- 1 Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Yu Chai
- 1 Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Jiao Jiao Li
- 2 Biomaterials and Tissue Engineering Research Unit, School of AMME, University of Sydney, Sydney, NSW, Australia
| | - Lin Du
- 3 Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou, People's Republic of China
| | - Ruizhe Tan
- 3 Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou, People's Republic of China
| | - Shenyu Yang
- 3 Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou, People's Republic of China
| | - Mei Tu
- 3 Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou, People's Republic of China
| | - Bin Yu
- 1 Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
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