scholarly journals Controlled Release of Strontium through Neutralization Reaction within a Methoxy(Polyethylene Glycol)-Polyesterc hydrogel

2017 ◽  
Vol 15 (2) ◽  
pp. 162-169 ◽  
Author(s):  
Sydney Peng ◽  
Zhi-Teng Lai ◽  
Ding-Wei Hong ◽  
I-Ming Chu ◽  
Po-Liang Lai

Background The aim of this study was to develop a minimally invasive hydrogel system that can release strontium ions, an element that has been shown to increase osteoblast proliferation and prohibit bone resorption, in a controlled manner. Methods SrCO3 was selected as the salt of choice due to potential acid neutralization reaction between SrCO3 and degradation by-products of methoxy(polyethylene glycol)- co-poly(lactic- co-glycolic acid) (mPEG-PLGA): namely, lactic acid and glycolic acid. SrCO3 was incorporated into mPEG-PLGA hydrogel, and the system was assessed for gelation properties, drug release and biocompatibility. Results SrCO3 incorporation at hydrogel to SrCO3 ratios of 5:1, 3:1 and 1:1 (wt%) did not compromise the thermosensitivity of mPEG-PLGA hydrogels. Furthermore, incorporation of SrCO3 at 1:1 ratio prevented copolymer self-catalysis and decreased hydrogel weight loss from 85% to 61% in vitro after 30 days. During the 30-day time frame, zero-order strontium release was observed and was correlated to hydrogel degradation and acidity. The addition of SrCO3 also improved in vivo hydrogel biocompatibility, due to moderation of acidic microenvironment and amelioration of inflammatory response. Conclusions These results showed that the described system is suitable for the extended release of strontium and exhibits potential for localized treatment for osteoporosis or as a bone void filler.

2015 ◽  
Vol 15 (5) ◽  
pp. 3710-3719 ◽  
Author(s):  
Liting Guo ◽  
Baoan Chen ◽  
Ran Liu ◽  
Ping Liu ◽  
Guohua Xia ◽  
...  

2020 ◽  
Vol 8 (15) ◽  
pp. 4334-4345 ◽  
Author(s):  
Hyun Joo Kim ◽  
Su Jung You ◽  
Dae Hyeok Yang ◽  
Jin Eun ◽  
Hae Kwan Park ◽  
...  

The aim of this study was to investigate the osteogenic potential of BMSCs seeded on RGD-conjugated methoxy polyethylene glycol-polycaprolactone (MP–RGD) in vitro and in vivo.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 235
Author(s):  
Luana Zerrillo ◽  
Karthick Babu Sai Sankar Gupta ◽  
Fons A.W.M. Lefeber ◽  
Candido G. Da Silva ◽  
Federica Galli ◽  
...  

Polymeric nanoparticles (NPs) find many uses in nanomedicine, from drug delivery to imaging. In this regard, poly (lactic-co-glycolic acid) (PLGA) and polyethylene glycol (PEG) particles are the most widely applied types of nano-systems due to their biocompatibility and biodegradability. Here we developed novel fluorinated polymeric NPs as vectors for multi-modal nanoprobes. This approach involved modifying polymeric NPs with trifluoroacetamide (TFA) and loading them with a near-infrared (NIR) dye for different imaging modalities, such as magnetic resonance imaging (MRI) and optical imaging. The PLGA-PEG-TFA NPs generated were characterized in vitro using the C28/I2 human chondrocyte cell line and in vivo in a mouse model of osteoarthritis (OA). The NPs were well absorbed, as confirmed by confocal microscopy, and were non-toxic to cells. To test the NPs as a drug delivery system for contrast agents of OA, the nanomaterial was administered via the intra-articular (IA) administration method. The dye-loaded NPs were injected in the knee joint and then visualized and tracked in vivo by fluorine-19 nuclear magnetic resonance and fluorescence imaging. Here, we describe the development of novel intrinsically fluorinated polymeric NPs modality that can be used in various molecular imaging techniques to visualize and track OA treatments and their potential use in clinical trials.


2019 ◽  
Vol 20 (10) ◽  
pp. 2500 ◽  
Author(s):  
Vrathasha Vrathasha ◽  
Hilary Weidner ◽  
Anja Nohe

Background: Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. Methods: Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. Results: Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. Conclusion: CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.


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