Systemic administration of enzyme-responsive growth factor nanocapsules for promoting bone repair

2019 ◽  
Vol 7 (4) ◽  
pp. 1675-1685 ◽  
Author(s):  
Hongzhao Qi ◽  
Lijun Yang ◽  
Xueping Li ◽  
Xiaolei Sun ◽  
Jin Zhao ◽  
...  

Taking the advantages of the unique physiological character of bone fracture, a systemic delivery platform of growth factors for bone repair based on nanocapsules was exploited.

2013 ◽  
Vol 24 (4) ◽  
pp. 299-307 ◽  
Author(s):  
Fernando Antonio Mauad de Abreu ◽  
Cynthia Lopes Ferreira ◽  
Gerluza Aparecida Borges Silva ◽  
Camila de Oliveira Paulo ◽  
Melissa Nunes Miziara ◽  
...  

This work evaluated the bone-forming potential of the platelet-derived growth factor isoform BB (PDGF-BB), insulin-like growth factor I (IGF-I), and mixed PDGF-BB/IGF-I delivered in liposomes compared with phosphate buffered saline (PBS), in the healing process of rat tooth sockets. One hundred and twelve Wistar rats were randomized into 7 groups of 16 animals each and were evaluated at 3, 7, 14 and 21 days after extraction of the maxillary second molars. The left sockets were treated with PBS (P), empty liposome (L), IGF-I in PBS (IP), IGF-I in liposome (IL), PDGF-BB in PBS (PDP), PDGF-BB in liposome (PDL) and both growth factors (GFs) together within liposomes (PDIL). The right sockets were filled with blood clot (BC). Histological and histomorphometric analyses were used to evaluate the formation of new bone and blood vessels. Immunohistochemistry was performed to evaluate the expression of osteocalcin and vascular endothelial growth factor (VEGF) during bone repair. Data were tested statistically using a Tukey's test according to a Dunn's analysis and Mann-Whitney U test followed by Kruskal-Wallis one-way analysis. Results were considered significant when p<0.05. A significantly higher percentage of bone trabeculae and a higher number of blood vessels were observed in the IL, PDL and PDIL groups (p<0.05). However, these GF-liposome groups had statistically similar results. Immunohistochemical assays first detected osteocalcin and VEGF expression at 3 days followed by a peak at 7 days. Lower immunoreactivity levels were observed in the BC, L, P, IP and PDP groups compared with the IL, PDL and PDIL groups (p<0.05). The results suggest that GFs carried by liposomes, either in isolated or mixed forms, enhanced the healing process in rat tooth sockets. The differential expression of the osteogenic markers VEGF and osteocalcin in the early phases of bone healing support these findings.


2001 ◽  
Vol 10 (4) ◽  
pp. 1-5 ◽  
Author(s):  
Gregory A. Helm ◽  
Hayan Dayoub ◽  
John A. Jane

In the prototypical method for inducing spinal fusion, autologous bone graft is harvested from the iliac crest or local bone removed during the spinal decompression. Although autologous bone remains the “gold standard” for stimulating bone repair and regeneration, modern molecular biology and bioengineering techniques have produced unique materials that have potent osteogenic activities. Recombinant human osteogenic growth factors, such as bone morphogenetic proteins, transforming growth factor–β, and platelet-derived growth factor are now produced in highly concentrated and pure forms and have been shown to be extremely potent bone-inducing agents when delivered in vivo in rats, dogs, primates, and humans. The delivery of pluripotent mesenchymal stem cells (MSCs) to regions requiring bone formation is also compelling, and it has been shown to be successful in inducing osteogenesis in numerous pre-clinical studies in rats and dogs. Finally, the identification of biological and nonbiological scaffolding materials is a crucial component of future bone graft substitutes, not only as a delivery vehicle for bone growth factors and MSCs but also as an osteoconductive matrix to stimulate bone deposition directly. In this paper, the currently available bone graft substitutes will be reviewed and the authors will discuss the novel therapeutic approaches that are currently being developed for use in the clinical setting.


2020 ◽  
Author(s):  
Aleczandria S. Tiffany ◽  
Marley J. Dewey ◽  
Brendan A.C. Harley

ABSTRACTTrauma induced injuries of the mouth, jaw, face, and related structures present unique clinical challenges due to their large size and complex geometry. Growth factor signaling coordinates the behavior of multiple cell types following an injury, and effective coordination of growth factor availability within a biomaterial can be critical for accelerating bone healing. Mineralized collagen scaffolds are a class of degradable biomaterial whose biophysical and compositional parameters can be adjusted to facilitate cell invasion and tissue remodeling. Here we describe the use of modified simulated body fluid treatments to enable sequential sequestration of bone morphogenic protein 2 and vascular endothelial growth factor into mineralized collagen scaffolds for bone repair. We report the capability of these scaffolds to sequester growth factors from solution without additional crosslinking treatments and show high levels of retention for individual and multiple growth factors that can be layered into the material via sequential sequestration steps. Sequentially sequestering growth factors allows prolonged release of growth factors in vitro and suggests the potential to improve healing of large-scale bone injury models in vivo. Future work will utilize this sequestration method to induce cellular activities critical to bone healing such as vessel formation and cell migration.


2021 ◽  
Vol 22 (2) ◽  
pp. 903
Author(s):  
Érica Resende Oliveira ◽  
Lei Nie ◽  
Daria Podstawczyk ◽  
Ahmad Allahbakhsh ◽  
Jithendra Ratnayake ◽  
...  

Shortcomings related to the treatment of bone diseases and consequent tissue regeneration such as transplants have been addressed to some extent by tissue engineering and regenerative medicine. Tissue engineering has promoted structures that can simulate the extracellular matrix and are capable of guiding natural bone repair using signaling molecules to promote osteoinduction and angiogenesis essential in the formation of new bone tissues. Although recent studies on developing novel growth factor delivery systems for bone repair have attracted great attention, taking into account the complexity of the extracellular matrix, scaffolding and growth factors should not be explored independently. Consequently, systems that combine both concepts have great potential to promote the effectiveness of bone regeneration methods. In this review, recent developments in bone regeneration that simultaneously consider scaffolding and growth factors are covered in detail. The main emphasis in this overview is on delivery strategies that employ polymer-based scaffolds for spatiotemporal-controlled delivery of both single and multiple growth factors in bone-regeneration approaches. From clinical applications to creating alternative structural materials, bone tissue engineering has been advancing constantly, and it is relevant to regularly update related topics.


1985 ◽  
Vol 110 (1_Suppla) ◽  
pp. S74
Author(s):  
R. GÄRTNER ◽  
W. GREIL ◽  
R. DEMHARTER ◽  
K. HORN

2021 ◽  
pp. 1-7
Author(s):  
Sarah Jarrin ◽  
Abrar Hakami ◽  
Ben Newland ◽  
Eilís Dowd

Despite decades of research and billions in global investment, there remains no preventative or curative treatment for any neurodegenerative condition, including Parkinson’s disease (PD). Arguably, the most promising approach for neuroprotection and neurorestoration in PD is using growth factors which can promote the growth and survival of degenerating neurons. However, although neurotrophin therapy may seem like the ideal approach for neurodegenerative disease, the use of growth factors as drugs presents major challenges because of their protein structure which creates serious hurdles related to accessing the brain and specific targeting of affected brain regions. To address these challenges, several different delivery systems have been developed, and two major approaches—direct infusion of the growth factor protein into the target brain region and in vivo gene therapy—have progressed to clinical trials in patients with PD. In addition to these clinically evaluated approaches, a range of other delivery methods are in various degrees of development, each with their own unique potential. This review will give a short overview of some of these alternative delivery systems, with a focus on ex vivo gene therapy and biomaterial-aided protein and gene delivery, and will provide some perspectives on their potential for clinical development and translation.


2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Irina A. Shurygina ◽  
Мichael G. Shurygin ◽  
Lubov V. Rodionova ◽  
Nataliya I. Ayushinova

AbstractObjectivesTo study the expression of growth factors in the regulation of tissue repair after peritoneal damage tissue response to peritoneal damage.MethodsExperimental study in 35 male Wistar rats determining the evolution over time of the tissue response to aseptic peritoneal damage. A standardized bowel and peritoneal lesions were created in the right lower quadrant by laparotomy. Then, tissular expression of growth factors was evaluated by multiplex polymerase chain reaction at seven timepoints between 6 h and 30 days, postoperatively.ResultsTissular responses of granulocyte-stimulating factors (Csf2, Csf3), connective tissue growth factor (Ctgf), epidermal growth factors and receptor (Egf, Egfr), fibroblast growth factors (Fgf2, 7 and 10), heparin binding EGF-like growth factor (Hbegf), hepatocyte growth factor (Hgf), insulin-like growth factor-1 (Igf1), mitogenic transforming growth factors (Tgfa, Tgfb1, Tgfbr3), and vascular endothelial growth factor A (Vegfa) were biphasic with a first expression peak at day 3, followed by a more pronounced peak at day 14.ConclusionsWe observed a long-lasting, widespread response of tissular growth factors for at least two weeks after peritoneal damage. To be clinically effective, the prophylaxis of postoperative adhesions might be needed for an extended period of time.


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 679
Author(s):  
Benedict-Uy Fabia ◽  
Joshua Bingwa ◽  
Jiyeon Park ◽  
Nguyen-Mihn Hieu ◽  
Jung-Hoon Ahn

Pseudomonas fluorescens, a gram-negative bacterium, has been proven to be a capable protein manufacturing factory (PMF). Utilizing its ATP-binding cassette (ABC) transporter, a type I secretion system, P. fluorescens has successfully produced recombinant proteins. However, besides the target proteins, P. fluorescens also secretes unnecessary background proteins that complicate protein purification and other downstream processes. One of the background proteins produced in large amounts is FliC, a flagellin protein. In this study, the master regulator of flagella gene expression, fleQ, was deleted from P. fluorescens Δtp, a lipase and protease double-deletion mutant, via targeted gene knockout. FleQ directs flagella synthesis, so the new strain, P. fluorescens ΔfleQ, does not produce flagella-related proteins. This not only simplifies purification but also makes P. fluorescens ΔfleQ an eco-friendly expression host because it will not survive outside a controlled environment. Six recombinant growth factors, namely, insulin-like growth factors I and II, beta-nerve growth factor, fibroblast growth factor 1, transforming growth factor beta, and tumor necrosis factor beta, prepared using our supercharging method, were successfully secreted by P. fluorescens ΔfleQ. Our findings demonstrate the potential of P. fluorescens ΔfleQ, combined with our supercharging process, as a PMF.


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