Mesoporous silica nanoparticles (MSNs) are attracting increasing interest for potential biomedical applications. With tailored mesoporous structure, huge surface area and pore volume, selective ...surface functionality, as well as morphology control, MSNs exhibit high loading capacity for therapeutic agents and controlled release properties if modified with stimuli-responsive groups, polymers or proteins. In this review article, the applications of MSNs in pharmaceutics to improve drug bioavailability, reduce drug toxicity, and deliver with cellular targetability are summarized. Particularly, the exciting progress in the development of MSNs-based effective delivery systems for poorly soluble drugs, anticancer agents, and therapeutic genes are highlighted.
Mesoporous silica nanoparticles (MSNs) with unique properties have attracted increasing interest for biomedical applications. Particularly, MSNs have shown great potential to deliver poorly soluble drugs, anticancer agents, and therapeutic genes. Display omitted
To improve its poor aqueous solubility and stability, the potential chemotherapeutic drug quercetin was encapsulated in soluplus polymeric micelles by a modified film dispersion method. With the ...encapsulation efficiency over 90%, the quercetin-loaded polymeric micelles (Qu-PMs) with drug loading of 6.7% had a narrow size distribution around mean size of 79.00 ± 2.24 nm, suggesting the complete dispersibility of quercetin in water. X-ray diffraction (XRD) patterns illustrated that quercetin was in amorphous or molecular form within PMs. Fourier transform infrared spectroscopy (FTIR) indicated that quercetin formed intermolecular hydrogen bonding with carriers. An
in vitro
dialysis test showed the Qu-PMs possessed significant sustained-release property, and the formulation was stable for at least 6 months under accelerated conditions. The pharmacokinetic study in beagle dogs showed that absorption of quercetin after oral administration of Qu-PMs was improved significantly, with a half-life 2.19-fold longer and a relative oral bioavailability of 286% as compared to free quercetin. Therefore, these novel soluplus polymeric micelles can be applied to encapsulate various poorly water-soluble drugs towards a development of more applicable therapeutic formulations.
Dry powder inhalers(DPIs) offer distinct advantages as a means of pulmonary drug delivery and have attracted much attention in the field of pharmaceutical science. DPIs commonly contain micronized ...drug particles which, because of their cohesiveness and strong propensity to aggregate, have poor aerosolization performance. Thus carriers with a larger particle size are added to address this problem. However, the performance of DPIs is profoundly influenced by the physical properties of the carrier, particularly their particle size, morphology/shape and surface roughness. Because these factors are interdependent, it is difficult to completely understand how they individually influence DPI performance.The purpose of this review is to summarize and illuminate how these factors affect drug–carrier interaction and influence the performance of DPIs.
Delivery of CRISPR (clustered regularly interspaced short palindromic repeats)/CRISPR‐associated protein‐9 (Cas9) represents a major hurdle for successful clinical translation of genome editing ...tools. Owing to the large size of plasmids that encode Cas9 and single‐guide RNA (sgRNA), genome editing efficiency mediated by current delivery carriers is still unsatisfactory to meet the requirement for its real applications. Herein, cationic polymer polyethyleneimine‐β‐cyclodextrin (PC), known to be efficient for small plasmid transfection, is reported to likewise mediate efficient delivery of plasmid encoding Cas9 and sgRNA. Whereas PC can condense and encapsulate large plasmids at high N/P ratio, the delivery of plasmid results in efficient editing at two genome loci, namely, hemoglobin subunit beta (19.1%) and rhomboid 5 homolog 1 (RHBDF1) (7.0%). Sanger sequencing further confirms the successful genome editing at these loci. This study defines a new strategy for the delivery of the large plasmid encoding Cas9/sgRNA for efficient genome editing.
Cationic polymer composed of low‐molecular‐weight polyethyleneimine and β‐cyclodextrin is exploited as the carrier for the delivery of plasmid DNA encoding Cas9 endonuclease and single‐guide RNA. Delivery of CRISPR (clustered regularly interspaced short palindromic repeats)/CRISPR‐associated protein‐9 plasmid mediated by this cationic polymer can result in efficient genome editing in vitro, which is superior to the “gold standard” polymeric delivery carrier.
Hypertrophic scar (HS) is an undesirable skin abnormality following deep burns or operations. Although intralesional multi-injection with the suspension of triamcinolone acetonide (TA) and ...5-fluorouracil (5-Fu) has exhibited great promise to HS treatment in clinical, the difference of metabolic behavior between TA and 5-Fu remarkably compromised the treatment efficacy. Besides, the traditional injection with great pain is highly dependent on the skill of the experts, which results in poor compliance. Herein, a bilayer dissolving microneedle (BMN) containing TA and 5-Fu (TA-5-Fu-BMN) with biphasic release profile was designed for HS therapy. Equipped with several micro-scale needle tips, the BMN could be self-pressed into the HS with uniform drug distribution and less pain. Both in vitro permeation and in vivo HS retention tests revealed that TA and 5-Fu could coexist in the scar tissue for a sufficient time period due to the well-designed biphasic release property. Subsequently, the rabbit ear HS model was established to assess therapeutic efficacy. The histological analysis showed that TA-5-Fu-BMN could significantly reduce abnormal fibroblast proliferation and collagen fiber deposition. It was also found that the value of scar elevation index was ameliorated to a basal level, together with the downregulation of mRNA and protein expression of Collagen I (Col I) and transforming growth factor-β1 (TGF-β1) after application of TA-5-Fu-BMN. In conclusion, the BMN with biphasic release profiles could serve as a potential strategy for HS treatment providing both convenient administrations as well as controlled drug release behavior.
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•A bilayer microneedle co-delivery system was designed for hypertrophic scar therapy.•The system contained rapid release triamcinolone and sustained-release 5- Fluorouracil.•The system was constructed to control the intralesional retention of different drugs.•The co-delivery system showed a superior therapeutic effect in hypertrophic scar.
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The resistance of Helicobacter pylori to classical antimicrobial treatment has become increasingly common, whereupon biofilms are considered to play an important role in the ...resistance mechanism. Here 10.2% of amoxicillin (AMX) and a novel anti H. pylori adhesion material pectin sulfate (PECS) loaded lipid polymer nanoparticles (LPN) were prepared, with rhamnolipid and phospholipids as the outer mixed lipids layer (RHL-PC-LPN). The size of RHL-PC-LPN was around 200nm, was negatively-charged, and showed sustained and complete drug release within 24h. In an in vitro study, H. pylori biofilm models were successfully established. RHL-PC-LPN, superior to PC-LPN (employing phospholipids only as the outer lipid layer), PECS+AMX (mixture of PECS and AMX) and AMX only, was proven to significantly eradicate H. pylori in the biofilm form. In accordance to our previous results, the RHL-PC-LPN group, together with the PC-LPN and PECS+AMX group, inhibited H. pylori from adhering to AGS cells. Investigating the underlying mechanisms contributing to the death of H. pylori caused by RHL-PC-LPN, we found that LPN could lower the antibiotic minimal inhibition concentration (MIC) to biofilm form from 125μg/ml to 15.6μg/ml. Furthermore, FITC-ConA labeled extracellular polymeric substances (EPS) were decreased in the RHL-PC-LPN group observed by a laser scanning confocal microscope. Therefore, we conclude that employing the mixed lipids of rhamnolipid and phospholipids as the outer layer of nanoparticles and PECS as the inner core produces a system capable of significantly disrupting H. pylori biofilm by eliminating the EPS as well as inhibiting the adherence and colonization of bacteria.
When antibiotic-resistant pathogenic bacteria pose a high threat to human health, bacterial multidrug efflux pumps become major contributors to the high-level antibiotic resistance in most ...microorganisms. Since traditional antibiotics are still indispensable currently, we report a dual drug delivery system to maximize the antibacterial efficacy of antibiotics by inhibiting efflux pumps in bacteria before their exposure to antibiotics. In this research, a microsphere/hydrogel composite was constructed from ciprofloxacin (Cip)-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres and ginsenoside Rh2 (G-Rh2) dispersed thermo-sensitive hydrogel to treat skin infections. In vitro drug release studies indicated that while G-Rh2 in hydrogel presented a faster and short-term release manner to rapidly inhibit the NorA efflux pumps, Cip showed a sustained and long-term release behavior to provide a local high concentration gradient for facilitating drug percutaneous penetration. The combination of Cip and G-Rh2 demonstrated a high degree of synergism against both methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), hence significantly improving their in vitro antibacterial activity and efficiency. Moreover, the antibacterial performance of the microsphere/hydrogel composite with a sequential release profile is superior to that of other formulations in mouse model of MRSA skin infections, indicating its great potential to treat antibiotic-resistant skin infections.
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The dissolving microneedle array (DMNA) offers a novel potential approach for transdermal delivery of biological macromolecular drugs and vaccines, because it can be as efficient as ...hypodermic injection and as safe and patient compliant as conventional transdermal delivery. However, effective needle drug distribution is the main challenge for clinical application of DMNA. This study focused on the mechanism and control of drug diffusion inside DMNA during the fabrication process in order to improve the drug delivery efficiency. The needle drug loading proportion (NDP) in DMNAs was measured to determine the influences of drug concentration gradient, needle drying step, excipients, and solvent of the base solution on drug diffusion and distribution. The results showed that the evaporation of base solvent was the key factor determining NDP. Slow evaporation of water from the base led to gradual increase of viscosity, and an approximate drug concentration equilibrium was built between the needle and base portions, resulting in NDP as low as about 6%. When highly volatile ethanol was used as the base solvent, the viscosity in the base rose quickly, resulting in NDP more than 90%. Ethanol as base solvent did not impact the insertion capability of DMNAs, but greatly increased the in vitro drug release and transdermal delivery from DMNAs. Furthermore, the drug diffusion process during DMNA fabrication was thoroughly investigated for the first time, and the outcomes can be applied to most two-step molding processes and optimization of the DMNA fabrication.
ABSTRACT
Purpose
To explore
in-situ
forming cocrystal as a single-step, efficient method to significantly depress the processing temperature and thus minimize the thermal degradation of ...heat-sensitive drug in preparation of solid dispersions by melting method (MM) and hot melt extrusion (HME).
Methods
Carbamazepine (CBZ)-nicotinamide (NIC) cocrystal solid dispersions were prepared with polymer carriers PVP/VA, SOLUPLUS and HPMC by MM and/or HME. The formation of cocrystal was investigated by differential scanning calorimetry and hot stage polarized optical microscopy. State of CBZ in solid dispersion was characterized by X-ray powder diffraction and optical microscopy. Interactions between CBZ, NIC and polymers were investigated by FTIR. Dissolution behaviors of solid dispersions were compared with that of pure CBZ.
Results
CBZ-NIC cocrystal with melting point of 160°C was formed in polymer carriers during heating process, and the preparation temperature of amorphous CBZ solid dispersion was therefore depressed to 160°C. The dissolution rate of CBZ-NIC cocrystal solid dispersion was significantly increased.
Conclusions
By
in-situ
forming cocrystal, chemically stable amorphous solid dispersions were prepared by MM and HME at a depressed processing temperature. This method provides an attractive opportunity for HME of heat-sensitive drugs.
When nanoparticles were introduced into the biological media, the protein corona would be formed, which endowed the nanoparticles with new bio-identities. Thus, controlling protein corona formation ...is critical to in vivo therapeutic effect. Controlling the particle size is the most feasible method during design, and the influence of media pH which varies with disease condition is quite important. The impact of particle size and pH on bovine serum albumin (BSA) corona formation of solid lipid nanoparticles (SLNs) was studied here. The BSA corona formation of SLNs with increasing particle size (120–480 nm) in pH 6.0 and 7.4 was investigated. Multiple techniques were employed for visualization study, conformational structure study and mechanism study, etc. “BSA corona-caused aggregation” of SLN2‒3 was revealed in pH 6.0 while the dispersed state of SLNs was maintained in pH 7.4, which significantly affected the secondary structure of BSA and cell uptake of SLNs. The main interaction was driven by van der Waals force plus hydrogen bonding in pH 7.4, while by electrostatic attraction in pH 6.0, and size-dependent adsorption was confirmed. This study provides a systematic insight to the understanding of protein corona formation of SLNs.
Different protein corona formation phenomena were shown in solid lipid nanoparticles (SLNS) with the various size and medium pH. The biological effect and the underlying interaction mechanisms were studied to provide a systematic perspective. Display omitted
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