Jyothsna Manikkath

Influence of peptide dendrimers and sonophoresis on the transdermal delivery of ketoprofen

The aim of this study was to determine the individual and combined effects of peptide dendrimers and low frequency ultrasound on the transdermal permeation of ketoprofen. Arginine terminated peptide dendrimers of varying charges (4+, 8+ and 16+, named as A4. A8 and A16 respectively) were synthesized and characterized. Ketoprofen was subjected to passive, peptide dendrimer-assisted and sonophoretic permeation studies (with and without dendrimer application) across Swiss albino mouse skin, both in vitro and in vivo. The studies revealed that the synthesized peptide dendrimers considerably increased the transdermal permeation of ketoprofen and displayed enhancement ratios of up to 3.25 (with A16 dendrimer), compared to passive diffusion of drug alone in vitro. Moreover, the combination of peptide dendrimer treatment and ultrasound application worked in synergy and gave enhancement ratios of up to 1369.15 (with ketoprofen-A16 dendrimer complex). In vivo studies demonstrated that dendrimer and ultrasound-assisted permeation of drug achieved much higher plasma concentration of drug, compared to passive diffusion. Comparison of transdermal and oral absorption studies revealed that transdermal administration of ketoprofen with A8 dendrimer showed comparable absorption and plasma drug levels with oral route. The excised mouse skin after in vivo permeation study with dendrimers and ultrasound did not show major toxic reactions. This study demonstrates that arginine terminated peptide dendrimers combined with sonophoresis can effectively improve the transdermal permeation of ketoprofen.

Skin delivery of epigallocatechin-3-gallate (EGCG) and hyaluronic acid loaded nano-transfersomes for antioxidant and anti-aging effects in UV radiation induced skin damage

Abstract The present work attempts to develop and statistically optimize transfersomes containing EGCG and hyaluronic acid to synergize the UV radiation-protective ability of both compounds, along with imparting antioxidant and anti-aging effects. Transfersomes were prepared by thin film hydration technique, using soy phosphatidylcholine and sodium cholate, combined with high-pressure homogenization. They were characterized with respect to size, polydispersity index, zeta potential, morphology, entrapment efficiency, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), in vitro antioxidant activity and ex vivo skin permeation studies. Cell viability, lipid peroxidation, intracellular ROS levels and expression of MMPs (2 and 9) were determined in human keratinocyte cell lines (HaCaT). The composition of the transfersomes was statistically optimized by Design of Experiments using Box–Behnken design with four factors at three levels. The optimized transfersome formulation showed vesicle size, polydispersity index and zeta potential of 101.2 ± 6.0 nm, 0.245 ± 0.069 and −44.8 ± 5.24 mV, respectively. FTIR and DSC showed no interaction between EGCG and the selected excipients. XRD results revealed no form conversion of EGCG in its transfersomal form. The optimized transfersomes were found to increase the cell viability and reduce the lipid peroxidation, intracellular ROS and expression of MMPs in HaCaT cells. The optimized transfersomal formulation of EGCG and HA exhibited considerably higher skin permeation and deposition of EGCG than that observed with plain EGCG. The results underline the potential application of the developed transfersomes in sunscreen cream/lotions for improvement of UV radiation-protection along with deriving antioxidant and anti-aging effects.

Peptide dendrimer-conjugates of ketoprofen: Synthesis and ex vivo and in vivo evaluations of passive diffusion, sonophoresis and iontophoresis for skin delivery

&NA; The aim of this study was to evaluate skin delivery of ketoprofen when covalently tethered to mildly cationic (2+ or 4+) peptide dendrimers prepared wholly by solid phase peptide synthesis. The amino acids glycine, arginine and lysine formed the dendrimer with ketoprofen tethered either to the lysine side‐arm (N&egr;) or periphery of dendrimeric branches. Passive diffusion, sonophoresis‐ and iontophoresis‐assisted permeation of each peptide dendrimer‐drug conjugate (D1–D4) was studied across mouse skin, both in vitro and in vivo. In addition, skin toxicity of dendrimeric conjugates when trialed with iontophoresis or sonophoresis was also evaluated. All dendrimeric conjugates improved aqueous solubility at least 5‐fold, compared to ketoprofen alone, while also exhibiting appreciable lipophilicity. In vitro passive diffusion studies revealed that ketoprofen in its native form was delivered to a greater extent, compared with a dendrimer‐conjugated form at the end of 24 h (Q24 h (&mgr;g/cm2): ketoprofen (68.06 ± 3.62) > D2 (49.62 ± 2.92) > D4 (19.20 ± 0.89) > D1 (6.45 ± 0.40) > D3 (2.21 ± 0.19). However, sonophoresis substantially increased the skin permeation of ketoprofen‐dendrimer conjugates in 30 min (Q30 min (&mgr;g/cm2): D4 (122.19 ± 7.14) > D2 (66.74 ± 3.86) > D1 (52.10 ± 3.22) > D3 (41.66 ± 3.22)) although ketoprofen alone again proved superior (Q30 min: 167.99 ± 9.11 &mgr;g/cm2). Next, application of iontophoresis was trialed and shown to considerably increase permeation of dendrimeric ketoprofen in 6 h (Q6 h (&mgr;g/cm2): D2 (711.49 ± 39.14) > D4 (341.23 ± 16.43) > D3 (89.50 ± 4.99) > D1 (50.91 ± 2.98), with a Q6 h value of 96.60 ± 5.12 &mgr;g/cm2 for ketoprofen alone). In vivo studies indicated that therapeutically relevant concentrations of ketoprofen could be delivered transdermally when iontophoresis was paired with D2 (985.49 ± 43.25 ng/mL). Further, histopathological analysis showed that the dendrimeric approach was a safe mode as ketoprofen alone. The present study successfully demonstrates that peptide dendrimer conjugates of ketoprofen, when combined with non‐invasive modalities, such as iontophoresis can enhance skin permeation with clinically relevant concentrations achieved transdermally. Graphical abstract Figure. No caption available.

Peptide Dendrimers in Delivery of Bioactive Molecules to Skin

The development of dendrimers as potential drug carriers or scaffolds is currently one of the most active areas of pharmaceutical and biomedical sciences. Peptide dendrimers, an alternative class of dendrimers, are wedge-like molecules of high molecular weight, composed of basic amino acids associated through amide and peptide bonds; these bonds are present both inside the branching core and on their external surface. Delivery of drugs through skin has many advantages compared to the traditional routes (ie, reduced adverse effects, noninvasiveness and resulting patient compliance, avoidance of first-pass metabolism, and allowing for sustained drug delivery). Unlike acrylate dendrimers, peptide dendrimers are broken down to simple and harmless amino acids, possess low toxicity, and are cost-effective to prepare and purify in bulk when synthesized using solid-phase peptide synthesis. Hence, amino acid–based peptide dendrimers are being regarded as highly favorable scaffolds for the efficient and safe delivery of drugs or genes. In this regard, their future in the transdermal delivery of therapeutics is certainly necessary.

Delving deeper into dermal and transdermal drug delivery: Factors and mechanisms associated with nanocarrier-mediated strategies

BACKGROUND Advances in material science and particle engineering have led to the development of a rapidly growing number of nanoparticulate carriers for drug and gene delivery. These carriers are increasingly being investigated in dermal and transdermal routes of drug administration. OBJECTIVE To critically examine and summarize the primary factors and mechanisms involved in nanocarriermediated dermal and transdermal delivery of drugs. METHOD Thorough literature search was undertaken, spanning the early development of nanocarrier-mediated dermal and transdermal drug delivery approaches, to the current state of the art, using online search tools. RESULTS Physicochemical, formulation, experimental and morphological factors, such as, material of construction or type of nanoparticle (NP), surface chemistry, particle size, particle shape, surface charge, dispersion medium, duration of exposure of skin to NPs, combination of NPs with physical agents, and aspects related to skin were identified and discussed. CONCLUSION The key factors and mechanisms which influence NPs-skin interactions in dermal and transdermal drug delivery are discussed in this article in-line with the current advances in the field.

Liposome-encapsulated diacyl glycerol and inositol triphosphate-induced delayed oocyte activation and poor development of parthenotes

Objective: To explore the ability of diacyl glycerol (DAG) and inositol triphosphate (IP3), two major secondary messengers in the calcium signaling pathway, in activating oocytes. Material and Methods: Oocyte cumulus complex obtained from superovulated Swiss albino mice were incubated in M16 medium with liposome-encapsulated 1,2-Dipalmitoyl-sn-glycerol (LEDAG) and/or IP3 for 3 h. Strontium chloride was used as positive control. The activation potential, ploidy status, and blastocyst rate was calculated. Results: Both DAG and IP3, individually, induced activation in ~98% of oocytes, which was significantly higher (p<0.01) than activation induced by strontium chloride (60%). Delayed pronucleus formation and a higher percentage of diploid parthenotes was observed in oocytes activated with LEDAG and/or IP3. However, these embryos failed to progress beyond the 6-8–cell stage. Only when the medium was supplemented with LEDAG (5 μg/mL) and IP3 (10 μg/mL) could activated oocytes progress till the blastocyst stage (5.26%), which was lower than the blastocyst rate in the positive controls (13.91%). Conclusion: The results of the present study indicate that DAG and IP3 can induce delayed oocyte activation and poor development of parthenotes in vitro.