C-REL-SPECIFIC SIRNA AND ITS USE FOR PREVENTING AND TREATING AUTOIMMUNE PSORIASIS

Abstract

The present invention provides a c-Rel-specific siRNA and its use for preventing and treating autoimmune psoriasis. In particular, the c-Rel-specific siRNAs have sequences as shown in SEQ ID Nos. 1-2 or SEQ ID Nos. 3-4. In the present invention, small interfering RNA (siRel) specific to c-Rel are employed to inhibit c-Rel biosynthesis, and prevent and treat autoimmune psoriasis by inhibiting inflammatory factors relating to IL-23/IL-17A inflammatory axis.

Claims

1. A c-Rel-specific small interfering RNA for preventing and/or treating autoimmune psoriasis, having sequences as shown in SEQ ID Nos. 1-2 or SEQ ID Nos. 3-4: TABLE-US-00005 (SEQ ID No. 1) sense strand 5′ CAACCGGACAUACCCGUCUdTdT 3′ (SEQ ID No. 2) antisense strand 5′ AGACGGGUAUGUCCGGUUGdTdT 3′; or (SEQ ID No. 3) sense strand 5′ CAACCGAACAUACCCUUCUdTdT 3′ (SEQ ID No. 4) antisense strand 5′ AGAAGGGUAUGUUCGGUUGdTdT 3′.

2. A pharmaceutical composition for preventing and/or treating autoimmune psoriasis, comprising a c-Rel-specific small interfering RNA.

3. The pharmaceutical composition according to claim 2, wherein the c-Rel-specific small interfering RNA have sequences as shown in SEQ ID Nos. 1-2 or SEQ ID Nos. 3-4.

4. The pharmaceutical composition according to claim 2, further comprising a PEG-PLL-PLLeu tri-block copolymer nano-micelle.

5. The pharmaceutical composition according to claim 4, wherein the pharmaceutical composition is a topical preparation for preventing and/or treating autoimmune psoriasis, and wherein the c-Rel-specific small interfering RNA has a concentration of 10-100 nM and the nano-micelle has a concentration of 10-20 μg/ml.

6. A method for preventing and/or treating the autoimmune psoriasis, comprising a step of administrating to a subject an effective amount of c-Rel-specific small interfering RNAs to inhibit c-Rel biosynthesis, so as to inhibit IL-23/IL-17A inflammatory axis in the subject with psoriasis.

7. The method according to claim 6, wherein the c-Rel-specific small interfering RNA have sequences as shown in SEQ ID Nos. 1-2 or SEQ ID Nos. 3-4.

8. The method according to claim 6, wherein a nano-material is used to carry the c-Rel-specific small interfering RNAs and transport them to the cytoplasm.

9. The method according to claim 8, wherein the nano-material is a PEG-PLL-PLLeu tri-block copolymer micelle.

10. The method according to claim 6, wherein the subject is a mammal or a human.

11. The method according to claim 6, used for preventing and/or treating autoimmune psoriasis of human by administrating intravenously, or by applying within skin lesion areas intradermally, subcutaneously or on the skin.

12. The method according to claim 11, wherein, the dosage of the siRel administrated intravenously is 0.3 mg/kg, and the corresponding dosage of the nano-micelle is 4.5 mg/kg, given at a frequency of once every three weeks; the dosage of the siRel administrated intradermally is 8 mg, and the corresponding dosage of the nano-micelle is 8 mg, given at a volume of 2 ml and a frequency of once every one week; the dosage of the siRel administrated subcutaneously is 16 mg, and the corresponding dosage of the nano-micelle is 16 mg, given at a volume of 4 ml and a frequency of once every one week; or the siRel is applied on the skin at a concentration of 10 nM, and the corresponding dosage of the nano-micelle is 10 μg/ml, given at a frequency of 1-3 times every one day, with 0.5 ml of the siRel nano-micelle suspension applied per 500 square centimeters for each application.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 illustrates an schematic illustration of preparation of the siRNA/PEG-PLL-PLLeu micelle suspension.

[0040] FIG. 2 illustrates a characterization of the siRNA/PEG-PLL-PLLeu nano-micelle, in which panel A shows a gel retardation assay for determining the capacity of the micelle in binding the siRNA; panel B shows the particle size and surface potential of the siRNA-carrying micellar mixture (N/P=15); and panels C and D show the determination of the efficiency of transfecting BMDC or BM20 by siRNA-carrying micellar mixtures having different N/P ratios. The values are shown as mean±standard deviation (n=3).

[0041] FIG. 3 illustrates in vitro silencing effect of the siRel/PEG-PLL-PLLeu nano-micelle, in which panel A-E show the relative expression of c-Rel or IL23p19 assayed by real-time quantitative PCR, in NIH3T3, RAW264.7 and BMDC stimulated with LPS for 4 hours or not stimulated after 24 hours of siNC or siRel treatment; panel F shows the protein level of IL23 in supernatant assayed by ELISA, in BMDC stimulated with LPS for 4 hours or not stimulated after 48 hours of siNC or siRel treatment; and panel G-H show that the siRel can reduce the expression of c-Rel at protein level, wherein panel H shows a chart of the quantitation of western blotting. The values are shown as mean±standard deviation (n=3), *: P<0.05; **: P<0.01; ***: P<0.001.

[0042] FIG. 4 illustrates the establishment of an IMQ-induced psoriasis model in mice, in which panel A shows the psoriasis phenotype at day 6 of IMQ induction of psoriasis in BALB/c mice (days 0-3: 65 mg/day; days 4-5: 80 mg/day; day 6: 100 mg/day); panel B shows scoring (0-4) of the mice skin lesions each day during the IMQ induction; and panel C shows the H & E staining of skin in the skin lesion areas of the mice of the control group and the IMQ-induced group on day 6. The values are shown as mean±standard deviation(n=3), unpaired t-test, *: P<0.05.

[0043] FIG. 5 illustrates siRel treatment can effectively control the development of mild psoriasis, in which panel A shows a chart of the treatment course for BALB/c mice with psoriasis where 8-11 weeks old mice were daily applied with imiquimod cream on the back for 8 consecutive days (days 0-3: 65 mg/day; days 4-5: 80 mg/day; days 6-7: 100 mg/day), intraperitoneally given siNC or siRel on days 1, 2, 4, and 6, and then sacrificed and sampled on day 8; panel B shows the phenotypes of the mice in the control group and the treatment group on day 8; panel C shows scoring (0-4) of skin lesions in mice from each group each day during the course of the treatment; and panel D shows the H & E staining of skin in the skin lesion areas of the mice from the control group and the treatment group. The values are shown as mean±standard deviation(n=13), unpaired t-test, *: P<0.05; ***: P<0.001.

[0044] FIG. 6 illustrates siRel treatment can effectively improve the symptom of skin lesions in moderate psoriasis, in which panel A shows a chart of the treatment course for psoriasis; and panel B shows the H & E staining of skin in the skin lesion areas of the mice from the control group (siNC) and the treatment group (siRel).

[0045] FIG. 7 illustrates the protein level of IL17A assayed by ELISA in the spleen cells of mice in the siRel treatment group. The values in this figure are shown as mean±standard deviation(n=5), unpaired t-test, *: P<0.05; **: P<0.01; ***: P<0.001.

[0046] FIG. 8 illustrates the expressions of IL-23p19, IL-17A, IL-1β, IL-6 and TNF-α assayed by real-time quantitative PCR after the siRel treatment. The values are shown as mean±standard deviation(n=5), unpaired t-test, *: P<0.05; **: P<0.01; ***: P<0.001.

[0047] FIG. 9 illustrates the expression of inflammatory factors in the skin of mice detected by Q-PCR on day 6 after treating the mice with moderate psoriasis.

DETAILED DESCRIPTION OF THE INVENTION

[0048] For a clearer understanding of the essence of the invention, the invention will now be described in more details by way of specific examples with reference to the accompanying drawings, but the invention is not limited thereto in any way. In the following examples, the experimental processes for which the detailed conditions are not specified are generally carried out in accordance with routine practice in the field or in accordance with the conditions recommended by the manufacturer.

Example 1

[0049] In this example, the efficacy of the c-Rel-specific siRNA (i.e., siRel) was verified in NIH3T3 and RAW264.7 cell lines (the NIH3T3 and RAW264.7 cell lines were purchased from ATCC) in in vitro experiments. Furthermore, bone marrow-derived dendritic cells (BMDC) were used as investigating objects to verify the silencing effect of the siRel. The details of the experiments were as follows:

[0050] 1. Design and Synthesis of c-Rel-Specific Small Interfering RNA (siRNA)

[0051] In this example, c-Rel-specific small interfering RNAs (siRel) were used to inhibit c-Rel synthesis, where the RNAs in mice have the sequences of

TABLE-US-00004 (SEQ ID No. 1) sense strand 5′ CAACCGGACAUACCCGUCUdTdT 3′ (SEQ ID No. 2) antisense strand 5′ AGACGGGUAUGUCCGGUUGdTdT 3′

[0052] These siRel sequences were synthesized by Shanghai JiMa Inc. and siNC was used as a general negative control. FAM-labeled siRels (siRel-FAM) were also synthesized by Shanghai JiMa Inc.

[0053] 2. Preparation of siRNA/PEG-PLL-PLLeu Micelle Suspension

[0054] PEG-PLL-PLLeu is a polyethylene glycol-polylysine-poly-leucine tri-block copolymer, synthesized by coworkers, MA Yifan and CAI Lintao, using NCA ring-opening polymerization (Deng, J. et al. Self-assembled cationic micelles based on PEG-PLL-PLLeu hybrid polypeptides as highly effective gene vectors. Biomacromolecules 13, 3795-3804, doi:10.1021/bm3012538 (2012)). In an aqueous solution, at a concentration greater than the critical micelle concentration, the amphiphilic tri-block copolymer could self-assemble to form micelles with a particle size of about 150 nm. In this case, poly-leucine segments aggregated to form the hydrophobic core of the micelle, polyethylene glycol formed the shell of the micelle, and the poly-lysine segments in the middle were protonated because they had a large amount of primary amino groups, resulting in a zeta potential of the micelle of about 43 mV. By electrostatic interaction, the nano-micelle could bind to the negatively-charged siRNA to form a positively-charged mixed suspension of siRNA-carrying micelles. In addition, because cell membrane was negatively charged, the siRNA-carrying nano-micelles were adsorbed on the cell membrane by electrostatic interaction, facilitating the endocytosis of the micelles by the cell.

[0055] Referring to FIG. 1, an appropriate amount of PEG-PLL-PLLeu lyophilized powder was weighed and dissolved in deionized water, and 1 mg/ml copolymer micelle suspension was prepared and then subjected to sterilization through a 0.22 μm filter. The OPTI-MEM diluted siRel was mixed with an equivalent volume of the copolymer suspension at different N/P ratios (a molar ratio of the primary amino groups in the copolymer micelle to the phosphate groups in siRel), and left still at room temperature for 30 min, to obtain a siRel-carrying copolymer micelle (siRel/PEG-PLL-PLLeu) suspension. The micelle suspension was dropped into a cell culture plate and mixed uniformly under gentle tapping, for cell transfection.

[0056] 3. Characterization of the siRNA/PEG-PLL-PLLeu Nano-Micelle

[0057] The siRel/PEG-PLL-PLLeu mixed at different N/P ratios prepared as described above were loaded on a 2% agarose gel, electrophoresed at 120 mV for 20 minutes by using a TAE buffer, and observed with a UV gel imaging device for gel retardation results. The particle size and zeta potential of the nano-micelles were measured at room temperature using a dynamic light scattering meter (Nano-ZSZEN3600) and analyzed with the Malvem Dispersion Technology Software 4.2 software.

[0058] FIG. 2 shows in A the siRNA-binding ability of the micelles determined by the gel retardation assay. As seen from the figure, when the N/P ratio is greater than or equal to 2, the copolymer micelle can carry all the siRNA.

[0059] FIG. 2 shows in B the particle size and surface potential of the siRNA-carrying micelle mixtures (N/P=15). The results show that the micelles particle size increases from about 148 nm to about 180 nm, and the zeta potential decreases from about 42 mV to about 38 mV, when the micelles and siRNA are mixed at a N/P ratio of 15.

[0060] FIG. 2 shows in C and D the determined results of the efficiency of transfecting BMDC or BM20 with siRNA-carrying micelle mixtures mixed at different N/P ratios. Flow cytometry results show that there is no significant difference between the transfection efficiency for BMDC and that for BM20 when the N/P ratio is 10, 15, or 20. When the N/P ratio is 15, the BMDC is transfected with the nano-micelle at an efficiency of about 45%, while BM20 is transfected at an efficiency of about 60%.

[0061] 4. In Vitro Silencing Experiment with siRel/PEG-PLL-PLLeu Nano-Micelle

[0062] METHOD: NIH3T3 and RAW264.7 cell lines were purchased from ATCC and cultured according to standard procedures. BMDC is obtained by primary isolation and induction. BALB/c mice were sacrificed by cervical dislocation, and femur and tibia were removed under sterile conditions. Bone marrow cells were rinsed out by pipetting PBS containing 2% FBS with a 1 ml syringe. The cell suspension was collected and resuspended with the erythrocyte lysate after centrifugation. The cells were washed three times with the culture medium 1 min after the lysis. Cells were suspended in the X-Vivo medium containing 20 ng/ml recombinant mouse GM-CSF and 10 ng/ml recombinant mouse IL-4, to prepare a cell suspension of 2×10.sup.6 cells/ml, which was then seeded into a 24-well plate, with 1 ml per well. Half-volume exchange of the culture medium was carried out on day 3 and day 5, and bone marrow-derived dendritic cells (BMDC) were obtained on day 6. In assessing the in vitro silencing effect of the siRel, NIH3T3, RAW264.7 or BMDC was seeded in 24-well plates into which the prepared siNC-carrying or siRel-carrying nano-micelles were added dropwise, until the siRNA concentration in the culture medium was 100 nM. 24 h after transfection, the cells was stimulated with LPS or not stimulated for 6 h and then collected, and the total RNA was extracted from the cells or tissues using the Trizol reagent. Reverse transcription was performed using oligo dT as a primer and the M-MLV Reverse Transcriptase, while the specific experimental procedures were performed according to the instructions of the Promega product. The expression level of c-Rel and IL-23p19 mRNA was then determined by real-time quantitative PCR using Thunderbird SYBR qPCR Mix with GAPDH as an internal reference. After 48 hours of transfection, BMDC was stimulated with LPS for 6 h. The supernatant was then collected and the concentration of IL23p19 was determined by ELISA, and the specific procedures were carried out according to Ebioscience's instructions. After 48 hours of transfection, BMDC was stimulated with LPS for 6 h and harvested, and nucleus proteins were extracted. The protein concentration was measured by the BCA method. The amount of c-Rel protein in the nucleus was measured by Western blotting.

[0063] FIG. 3 shows the in vitro silencing effect when siRel is delivered using PEG-PLL-PLLeu nano-micelles. In panels A-C, it is demonstrated that the siRel can effectively reduce the level of c-Rel mRNA in NIH 3T3 (P<0.01) and the siRel can significantly decrease the mRNA level of c-Rel and IL23p19 in the RAW 264.7 cell line (P<0.05). When the PEG-PLL-PLLeu micelles are used to transport siRNA to BMDC and the silencing effect of the siRel is evaluated, panels D-E demonstrate that the siRel can significantly reduce the mRNA expression of c-Rel and IL23p19 in BMDC at mRNA level (P<0.05). Panel F shows that the siRel can also reduce the expression of IL23 at protein level (P<0.01). Panels G-H demonstrate that the siRel can reduce the expression of c-Rel at protein level, where panel H is a quantitative chart of the western blotting.

Example 2

[0064] Psoriasis treatment can be categorized into early stage, mid-stage and late stage treatments, in accordance with mild, moderate, and severe psoriasis in terms of severity thereof, respectively. In this experiment, the therapeutic effect of siRel was evaluated in mice with mild and moderate psoriasis. The IMQ-induced psoriasis model is similar to human psoriasis in terms of the pathological changes, and is an ideal model for studying psoriasis. IMQ is a toll-like receptor (TLR) 7/8 agonist, and when applied to the skin of mice, can activate dendritic cells and macrophages through the TLR pathway and activate keratinocytes through the TLR-independent pathways, promote the secretion of IFN-α, TNF-α, and other proinflammatory factors, and recruit inflammatory cells into the skin, resulting in psoriasis-like lesions and histological changes. In addition, Leslie van der Fits et al. have confirmed that the IL-23/IL-17A inflammatory axis played a critical role in the IMQ-induced psoriasis model. In contrast to the reports in the art, in the experiment in this Example in the present invention, the given IMQ dosage was increasing, because different IMQ drug manufacturers and different feeding environments for mice require different dosages for psoriasis induction.

[0065] 1. Construction of IMQ-Induced Psoriasis Model

[0066] BALB/c mice were anesthetized by intraperitoneal injection of 10% chloral hydrate (300 mg/kg), followed by removing of the hair on the back to form an exposed area of about 2 cm×3 cm. IMQ was applied daily (days 0-3: 65 mg/day; day 4-day 5: 80 mg/day; day 6-day 7: 100 mg/day), and the skin of the mice was observed daily and scored for the formation of scales. The criteria of scoring is as follows: 0, no; 1, mild; 2, moderate; 3, severe; 4, critical. Scores of mice from each group were averaged and then plotted as a trend line, and the changes to the skin lesions in each group were observed.

[0067] 2. siRel Treatment of Mice with Mild Psoriasis

[0068] During the construction of the psoriasis model in mice, mice having a psoriasis score of 0.5 were treated by administration of siRNA drugs. The mice with psoriasis were randomly divided into a control group (siNC) and a treatment group (siRel), and were treated on days 1, 2, 4, 6, respectively with the siNC/PEG-PLL-PLLeu and siRel/PEG-PLL-PLLeu micelle suspensions, wherein the siRNA dose was 500 pmol and the micelle dose was 100 μg. Mouse skin was observed daily and scored for the formation of scales. Mouse skin was taken on day 8 when the lesion tissues were clipped from mice in each group at the same location following a nine-grid approach, and fixed in 4% paraformaldehyde. After OCT embedding, slices having a thickness of 7 μm were obtained by cryotomy. H & E staining was then performed, and the changes to the skin thickness from mice in each group were observed.

[0069] 3. siRel Treatment of Mice with Moderate Psoriasis

[0070] During the construction of the psoriasis model in mice, mice having a score of 2 were treated by administration of siRNA drugs. The mice with psoriasis were randomly divided into a control group (siNC) and a treatment group (siRel), and were treated on days 3, 4, 5, 6, 7, respectively with the siNC/PEG-PLL-PLLeu and siRel/PEG-PLL-PLLeu micelle suspensions, wherein the siRNA dose was 500 pmol and the micelle dose was 100 μg. Mouse skin was observed daily and scored for the formation of scales. Mouse skin was taken on day 8 when the lesion tissues were clipped from mice in each group at the same location following a nine-grid approach, and fixed in 4% paraformaldehyde. After OCT embedding, slices having a thickness of 7 μm were obtained by cryotomy. H & E staining was then performed, and the changes to the skin thickness from mice in each group.

[0071] FIG. 4 shows the construction of a psoriasis model in mice using IMQ. In this figure, panel A demonstrates the psoriasis phenotype of mice in the control group and the IMQ-induced group on day 7, where apparent scales can be observed on the back of the mice in the IMQ-induced group. Panel B shows the scoring of the scale-like symptoms in the process of the psoriasis induction using IMQ, in which it can be found that scale scores of the mice in the induction group keep increasing while the control group shows almost no scale symptom, significant (P<0.05) on day 4,5,6. Panel C shows the H & E staining results of the skin sections from the mice in the control group and the IMQ-induced group on day 6, in which it can be found that the skin thickness of the mice in the IMQ-induced group is substantially thickened as compared to that of the control group. These data suggest that the IMQ dosage used in this experiment may successfully induce the psoriasis model in mice.

[0072] FIG. 5 shows the efficacy of in vivo treatment of mild psoriasis by delivering siRel with PEG-PLL-PLLeu nano-micelles. In this figure, panel A shows the course of the treatment for BALB/c mice psoriasis. Panel B shows the psoriasis symptoms of the mice on day 8, in which it may be seen that the psoriasis-like lesions in the treatment group are substantially controlled. Panel C shows the scoring of mouse psoriasis-like symptoms, in which it may be found that the psoriasis score of the mice in the treatment group remains at a relatively low level while the psoriasis score of the mice in the control group is increasing, significant (P<0.05) on day 7 and 8. Panel D shows the H & E staining results of the skin sections from the mice in the treatment group and the control group, in which it may be found that the skin of the treated group is thinner than that of the control group, and the inflammatory cells infiltrated into the skin of the mice in the treated group are significantly reduced. These data suggest that siRel is able to effectively control the development of mild autoimmune psoriasis in mice.

[0073] FIG. 6 shows the efficacy of in vivo treatment of moderate psoriasis by delivering siRel with PEG-PLL-PLLeu nano-micelles. In this figure, panel A shows the course of the treatment for BALB/c mice psoriasis. Panel B shows the scoring of mouse psoriasis-like symptoms, in which it may be found that the psoriasis score of the mice in the treatment group keeps decreasing while the psoriasis score of the mice in the control group remains around score 2, significant (P<0.001) on day 8. Panel C shows the H & E staining results of the skin sections from the mice in the treatment group and the control group, in which it may be found that the skin of the treated group was thinner than that of the control group. These results suggest that siBel is able to effectively improve the symptoms of moderate autoimmune psoriasis in mice.

[0074] 4. ELISA Assaying of the Level of IL-17A Production in Mouse Spleen Cells

[0075] During the treatment of mice with mild psoriasis, the mice were sacrificed by cervical dislocation on day 2, 6, and 8, and the spleens of the psoriasis mice in the treatment group and the control group were taken and pulverized into cell suspensions. 2×10.sup.6 cells in a 500 μl culture system were inoculated in a 48-well plate. 48 h after stimulation with or without 0.5 μg/ml anti-CD3 antibodies and anti-CD28 antibodies, the supernatant was collected and assayed by enzyme-linked immunosorbent assay (ELISA) for the IL-17A level. The ELISA kit was purchased from Ebioscience, and the specific procedures were followed according to the instructions.

[0076] FIG. 7 shows the level of IL-17A production in the mouse spleen cells detected by ELISA on day 2, 6, and 8 during the treatment of mice with mild psoriasis. The results suggest that on day 2, 6, and 8, the secretion of IL17A in the spleen cells of the treated group is significantly lower than that in the control group (P<0.05), indicating that siRel can effectively reduce the level of IL-17A production in spleen cells of mice with psoriasis.

[0077] 5. Q-PCR Detection of Expression of IL-23/IL-17A Inflammatory Axis-Related Inflammatory Factors in Mouse Skin

[0078] In the treatment of mice with mild psoriasis, lesion tissues were clipped on day 2 and 6 from the mice in each group at the same location following a nine-grid approach, placed into liquid nitrogen, and then pulverized into powder, into which the Trizol reagent to extract total RNA from the skin. Using oligo dT as a primer, reverse transcription was performed with the M-MLV Reverse Transcriptase, following the experimental operations according to the instructions of the Promega product. Then, a real-time quantitative PCR was performed by using Thunderbird SYBR qPCR Mix, with GAPDH as an internal reference, to measure the relative expression of inflammatory factors such as IL-23p19, IL-17A, IL-1β, IL-6, and TNF-α.

[0079] FIG. 8 shows the expression level of inflammatory factors detected by Q-PCR in mouse skin on day 2 and 6 during the treatment of mice with mild psoriasis. The results suggest that the levels of TNF-α in the skin from the mice in the treatment group and the control group decrease slightly (P<0.05), with no difference detected on day 8. In addition, the levels of IL23p19 and IL6 in the skin from the mice in the treated group significantly decrease on day 2 and day 6 (P<0.05). Moreover, as detected in the present invention, the expression levels of IL17A and IL-1β in the skin from the mice in the treated group and the control group show no difference on day 2 but a significant decrease in the treated group (P<0.01) on day 6. The above results indicate that the inflammatory response in the skin from the mice with mild psoriasis in the treated group is controlled to certain extent. FIG. 9 shows the Q-PCR detected expression level of inflammatory factors in the skin of mice with moderate psoriasis on day 6 after the treatment. The results suggest that the expression levels of IL-1β, IL-6, IL-23p19, IL-17A, and IFN-γ in the skin from the mice with moderate psoriasis in the treated group are significantly reduced as compared to those in the control group on day 6 after the treatment (P<0.05). However, there was no significant difference in the expression levels of IL-12p35 and TNF-α. The above results suggest that the inflammatory response in the skin from the mice with moderate psoriasis in the treated group is substantially improved.

[0080] Although specific embodiments of the invention have been described above, the scope of the invention should not be limited thereto. Any changes and substitutions that can be contemplated by persons skilled in the art without creative efforts in view of the technical scope disclosed in the invention are intended to be encompassed in the protection scope of the present invention.