Anti-inflammatory Chitosan/Poly-γ-glutamic acid nanoparticles control inflammation while remodeling extracellular matrix in degenerated intervertebral disc.
Intervertebral disc (IVD) degeneration is one of the most common causes of low back pain (LBP), the leading disorder in terms of years lived with disability. Inflammation can play a role in LPB, while impairs IVD regeneration. In spite of this, different inflammatory targets have been purposed in the context of IVD regeneration. Anti-inflammatory nanoparticles (NPs) of Chitosan and Poly-(γ-glutamic acid) with a non-steroidal anti-inflammatory drug, diclofenac (Df), were previously shown to counteract a pro-inflammatory response of human macrophages. Here, the effect of intradiscal injection of Df-NPs in degenerated IVD was evaluated. For that, Df-NPs were injected in a bovine IVD organ culture in pro-inflammatory/degenerative conditions, upon stimulation with needle-puncture and interleukin (IL)-1β. Df-NPs were internalized by IVD cells, down-regulating IL-6, IL-8, MMP1 and MMP3, and decreasing PGE2 production, compared with IL-1β-stimulated IVD punches. Interestingly, at the same time, Df-NPs promoted an up-regulation of extracellular matrix (ECM) proteins, namely collagen type II and aggrecan. Allover, this study suggests that IVD treatment with Df-NPs not only reduces inflammation, but also delays and/or decreases ECM degradation, opening perspectives to new intradiscal therapies for IVD degeneration, based on the modulation of inflammation.



Degeneration of the IVD is an age-related progressive process considered to be the major cause of spine disorders. The pro-inflammatory environment and biomechanics of the degenerated IVD is a challenge for regenerative therapies. The novelty of this work is the intradiscal injection of an anti-inflammatory therapy based on Chitosan (Ch)/Poly-(γ-glutamic acid) (γ-PGA) nanoparticles (NPs) with an anti-inflammatory drug (diclofenac, Df), previously developed by us. This drug delivery system was tested in a pro-inflammatory/degenerative intervertebral disc ex vivo model. The main findings support the success of an anti-inflammatory therapy for degenerated IVD that not only reduces inflammation but also promotes native IVD matrix production.
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, 89081 Ulm, Germany; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Graciosa Q
GQ
Teixeira
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Catarina
C
Leite Pereira
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Flávia
F
Castro
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Joana R
JR
Ferreira
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
Maria
M
Gomez-Lazaro
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
Paulo
P
Aguiar
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Mário A
MA
Barbosa
Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, 89081 Ulm, Germany.
Cornelia
C
Neidlinger-Wilke
Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal. Electronic address: raquelg@ineb.up.pt.
Raquel M
RM
Goncalves
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002417:Cattle; D048271:Chitosan / Q000494:pharmacology*; D004705:Endocytosis / Q000187:drug effects; D005109:Extracellular Matrix / Q000378:metabolism*; D007249:Inflammation / Q000188:drug therapy* / Q000473:pathology; D007267:Injections; D055959:Intervertebral Disc Degeneration / Q000473:pathology* / Q000628:therapy*; D053758:Nanoparticles / Q000737:chemistry*; D009924:Organ Culture Techniques; D010316:Particle Size; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D014022:Tissue Survival / Q000187:drug effects
D000893:Anti-Inflammatory Agents; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D048271:Chitosan
Diclofenac; Inflammation; Intervertebral disc; Nanoparticles; Organ culture